SAT Prep: Test 5 Section 9 Part 3 Video

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SAT Prep: Test 5 Section 9 Part 3

SAT Prep: Test 5 Section 9 Part 3 Welcome back on the problem number 10. Philip used four pieces of masking tape, each six inches long so four pieces each six inches. Philip had a 300 foot each six inches long to put up each of his posters. Okay, so that’s for each poster, good enough. Philip had a 300 foot roll of masking tape when he started, so he starts with 300 feet. I can only tell you that some unit conversion will happen because it’s starting about six inches here and they took about 300 feet here. If no tape was wasted which of the following represents the number of feet? And they underlined it of masking tape that was left on the roll after he put up the end posters. And they are actually are telling us that 12 inches are equal to a foot in case you aren’t from this planet, so how do we do this? Well, let’s see after he put up end posters, so he’s going to put an n poster, so he’s going to start off. Well, how much tape will he used? So for each of those n posters how much he’ll use? Let’s see if he use these four pieces times six inches, but we want to go in the feet right? We want to know how many are left, so let’s just convert immediately to feet. Six inches is equal to how many feet? Well, it’s half a foot right? Six over 12 inches so it equals one half of foot. So, he does four pieces for each poster and each of those pieces is one half a foot and now we’re immediately in feet length so this is how much he uses, so he will use so four times one half is just two so he uses two end feet. So if he starts with 300 feet the amount that he has left is what he started minus what he used. He used two end feet so he starts with 300 feet minus two n feet, so that’s the expression. That’s choice B. Next problem, problem 11, in the x-y coordinate plane, line M is the reflection of line L about the x axis. If the slope of M is equal to minus 4/5, what is the slope of L? So, you should be hopefully be able to do this on the real exam without having to draw it or you can actually just draw a really quick and dirty one and that actually probably would do the job for you, so minus 4/5 that means its reflection about the x axis, so let’s draw a line M. Now let’s just assume that the origin is here. They don’t tell us that but you know they don’t tell it’s not that that’s zero, one, two, three, four, five. This is one, two, three, four and do here one, two, three, and four. I just want to draw so that you can understand. So, four minus four this is five. So we know line M. For every five it goes to the right and goes down four so this could be a legitimate line M right here. It can be like this. Line M could look like that right? So a reflection about the x axis if I were to reflect to about the x axis, alright this is the x axis right here so I just want to take it and flip it over the x axis. It will look like this. Now, I’m still not using the line tool. Now I’m using the line two. It would look like that, alright. So, what’s the slope here? Well, for every five I go to the right I moved up four so a change in y and so let me make sure that this is line M. This is line L so change in y over change in x where line L is equal to change in y is positive four over five and it shouldn’t take you that long to do it. One day you just can do as well. You can just do real quick and dirty one just like well I have something with the negative slope. Let’s say a negative really shallow slope like that. If I flip it it’s going to have the same slope, or it’s going to be a positive slope but still it’s going to be shallow, so it’s going to be like the same magnitude. It will just be you know your flip design, so the answer is B, four over five. I did this just to give you an intuition. The next problem or to let you know why I got it wrong you should get it wrong. Anyway, problem number 12, if n is equal to 3p, for what value of p is n equal to p? This is kind of crazy and at first that’s what they are saying then I read one of the choices because no matter what n is equal to 3p, right? There’s no circumstance. Well, sorry I was incorrect. There is a circumstance in which n is equal to 3p.For example you could say that you know well, what was the circumstance? Well, as long as p is not zero, n is going to be exactly 3 times p, right? But then in our statement I just told you the answer they both can be zero if p is zero then three times zero is zero, so there’s no real Algebra right there. You just kind of to realize that zero is a choice, and if you look at the choices you merely see choice A is zero try it out you say, “Oh, well, if p is zero then n is also zero so that n would equal p. So, next problem, problem 13, those are one of those problems and in some ways are so easy that you waste time on it making sure you didn’t miss something. Let’s draw what they drew, so you have a line like that, and then I have a line like that, and this is line L. This is y degrees. This is line M. This is x degrees and this is line N right here. In the figure above if z, they tell us this is z right there. This is z. In the figure above if z is equal to 30, what is the value of x + y, x + y is what? Well, what can we figure out? What do we know about this angle right here? That’s supplementary to y right? So this is kind of the angle being, but we’re going to have a little of where variables are normal. It’s supplementary to y, so this is going to be 180 minus y because y plus this angle are going to have to equal 180, right? And for the exact same reason this angle right here is 180 minus x, and what do we know? We know this angle plus this angle plus z is equal to 180, so let’s write that down. This angle 180 minus y plus this angle plus 180 minus x plus z is equal to 180 because they are all in the same triangle. So let’s try our best to simplify this where we can immediately get rid off of one of the 180s on that side and that becomes zero, z is 30, right? So let’s simplify it. We get minus y minus x and then you have 180 plus 30 plus 210 is equal to zero. Now, let’s add x and y to both sides. I’m kind of just keeping in step because add x to both sides and then add y to both sides. If you add x and y to both sides you’ll get 210 is equal to x + y. That’s the answer. They want to know what x + y is and that is choice D. And so the trick here is really saying well, they only gave us z. The only thing I know is z is in the triangle with this angle and this angle, and let me express those two angles in terms of x and y because they are supplementary to x and y. See you in the next video.

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SAT Prep: Test 5 Section 9 Part 3

Welcome back on the problem number 10. Philip used four pieces of masking tape, each six inches long so four pieces each six inches. Philip had a 300 foot each six inches long to put up each of his posters. Okay, so that’s for each poster, good enough.

Philip had a 300 foot roll of masking tape when he started, so he starts with 300 feet. I can only tell you that some unit conversion will happen because it’s starting about six inches here and they took about 300 feet here. If no tape was wasted which of the following represents the number of feet? And they underlined it of masking tape that was left on the roll after he put up the end posters.

And they are actually are telling us that 12 inches are equal to a foot in case you aren’t from this planet, so how do we do this? Well, let’s see after he put up end posters, so he’s going to put an n poster, so he’s going to start off. Well, how much tape will he used? So for each of those n posters how much he’ll use? Let’s see if he use these four pieces times six inches, but we want to go in the feet right? We want to know how many are left, so let’s just convert immediately to feet. Six inches is equal to how many feet? Well, it’s half a foot right? Six over 12 inches so it equals one half of foot.

So, he does four pieces for each poster and each of those pieces is one half a foot and now we’re immediately in feet length so this is how much he uses, so he will use so four times one half is just two so he uses two end feet. So if he starts with 300 feet the amount that he has left is what he started minus what he used. He used two end feet so he starts with 300 feet minus two n feet, so that’s the expression. That’s choice B.

Next problem, problem 11, in the x-y coordinate plane, line M is the reflection of line L about the x axis. If the slope of M is equal to minus 4/5, what is the slope of L?
So, you should be hopefully be able to do this on the real exam without having to draw it or you can actually just draw a really quick and dirty one and that actually probably would do the job for you, so minus 4/5 that means its reflection about the x axis, so let’s draw a line M. Now let’s just assume that the origin is here. They don’t tell us that but you know they don’t tell it’s not that that’s zero, one, two, three, four, five. This is one, two, three, four and do here one, two, three, and four. I just want to draw so that you can understand.

So, four minus four this is five. So we know line M. For every five it goes to the right and goes down four so this could be a legitimate line M right here. It can be like this. Line M could look like that right? So a reflection about the x axis if I were to reflect to about the x axis, alright this is the x axis right here so I just want to take it and flip it over the x axis. It will look like this.

Now, I’m still not using the line tool. Now I’m using the line two. It would look like that, alright. So, what’s the slope here? Well, for every five I go to the right I moved up four so a change in y and so let me make sure that this is line M. This is line L so change in y over change in x where line L is equal to change in y is positive four over five and it shouldn’t take you that long to do it.

One day you just can do as well. You can just do real quick and dirty one just like well I have something with the negative slope. Let’s say a negative really shallow slope like that. If I flip it it’s going to have the same slope, or it’s going to be a positive slope but still it’s going to be shallow, so it’s going to be like the same magnitude. It will just be you know your flip design, so the answer is B, four over five. I did this just to give you an intuition.

The next problem or to let you know why I got it wrong you should get it wrong. Anyway, problem number 12, if n is equal to 3p, for what value of p is n equal to p? This is kind of crazy and at first that’s what they are saying then I read one of the choices because no matter what n is equal to 3p, right?

There’s no circumstance. Well, sorry I was incorrect. There is a circumstance in which n is equal to 3p.For example you could say that you know well, what was the circumstance? Well, as long as p is not zero, n is going to be exactly 3 times p, right? But then in our statement I just told you the answer they both can be zero if p is zero then three times zero is zero, so there’s no real Algebra right there. You just kind of to realize that zero is a choice, and if you look at the choices you merely see choice A is zero try it out you say, “Oh, well, if p is zero then n is also zero so that n would equal p.

So, next problem, problem 13, those are one of those problems and in some ways are so easy that you waste time on it making sure you didn’t miss something. Let’s draw what they drew, so you have a line like that, and then I have a line like that, and this is line L. This is y degrees. This is line M. This is x degrees and this is line N right here.

In the figure above if z, they tell us this is z right there. This is z. In the figure above if z is equal to 30, what is the value of x + y, x + y is what? Well, what can we figure out? What do we know about this angle right here? That’s supplementary to y right? So this is kind of the angle being, but we’re going to have a little of where variables are normal. It’s supplementary to y, so this is going to be 180 minus y because y plus this angle are going to have to equal 180, right?

And for the exact same reason this angle right here is 180 minus x, and what do we know? We know this angle plus this angle plus z is equal to 180, so let’s write that down. This angle 180 minus y plus this angle plus 180 minus x plus z is equal to 180 because they are all in the same triangle.

So let’s try our best to simplify this where we can immediately get rid off of one of the 180s on that side and that becomes zero, z is 30, right? So let’s simplify it. We get minus y minus x and then you have 180 plus 30 plus 210 is equal to zero. Now, let’s add x and y to both sides. I’m kind of just keeping in step because add x to both sides and then add y to both sides. If you add x and y to both sides you’ll get 210 is equal to x + y. That’s the answer. They want to know what x + y is and that is choice D.

And so the trick here is really saying well, they only gave us z. The only thing I know is z is in the triangle with this angle and this angle, and let me express those two angles in terms of x and y because they are supplementary to x and y. See you in the next video.

Transcription by: Scribe4you Transcription Services

SAT Prep: Test 5 Section 9 Part 3

SAT Prep: Test 5 Section 9 Part 3 -

SAT Prep: Test 5 Section 9 Part 3 -