Explanation for Question 3 From the Math (Calc) Section on the 2019 April Sat
Okay. For number three, it says, Y is equal to X plus one, 2 half, and Z is equal to two X minus three, 3 which of the following is equivalent to Y plus Y times Z. 4 So since all of these answer choices are in terms of X and 5 we have Y and Z in terms of X already, 6 we can just plug in Y and Z into Y plus Y times C. 7 So I do that. 8 We know Y is equal to X plus one half, 9 and then we have plus Y again. 10 So X plus one half times, 11 Z two X minus three. 12 So I took this and plugged in each part. 13 So here is the why, there's why again, 14 and there's busy. So now I'm going to foil this out. 15 So that gives me two X squared, 16 minus three X. Then we have one, 17 half times, two X just gives me X and then negative three 18 times one half is negative three house, 19 and we are still adding this X plus one half here. 20 So now we can take this and combine like terms to get our answer. 21 So two X squared has nothing to combine with. 22 So I'll write it first. Then we have X minus 23 three, X is negative two X plus another X leaves 24 me with negative one X or just negative X. 25 And then we have one half minus 26 three halves that gives you negative two halves, 27 which is also negative one. 28 So the answer is two X squared minus X minus one, 29 which is a.