Explanation for Question 2 From the Math (No Calc) Section on the Official Sat Practice Test 9
Question two asks us, which of the following is equivalent to two times X 2 squared, minus X plus three times X squared minus X. 3 So to do this, we're just going to simplify and kind of solve through. 4 So it's faded out a little bigger below so we can see it. 5 We've got two times X squared minus X plus three times X squared 6 minus X. All right. 7 So let's, um, multiply this out and we 8 get two X squared minus two X plus 9 three X squared, minus three X. 10 So now grouping like terms. We have two X squared plus three X squared 11 is equal to five X squared and we have minus two X or excuse 12 me, we have minus two X minus three X, which is equal to minus 13 five X. So we have five X squared minus five X, 14 which is equal to a, another quick hint here. 15 Another way to think about it is going back, 16 um, to our initial stage of this expression. 17 We can see that this from right here is the same, 18 so we can see that we're going to have two 19 X squared minus X plus three X squared minus X. 20 And knowing that that term is the same. We can see this basically, 21 um, adding, 22 if you almost substitute in the value of Y for example, 23 it's two Y plus three Y so we'd get five Y and then plugging 24 back in the original term, 25 we get five times X squared, minus X, 26 which sends solving out. We can get five X squared minus five X. 27 So that's just another quick way to do it. And that's when we get 28 to answer.