Explanation for Question 17 From the Math (No Calc) Section on the Official Sat Practice Test 8
So question number 17 gives us two expressions and they ask us, 2 what is the sum of a, B and C? 3 So the first thing we can ask ourselves is how do we figure out 4 what a, B and C are. We need to use this, 5 this form here, but how do we get to that forum? 6 And if we look earlier in the question, we see that references a sum 7 of these two expressions. So what I can do is add those two expressions 8 together, right? I have negative two X squared plus X plus 31, 9 plus the second expression, which is three X squared, 10 plus seven X minus eight. 11 So in order to add them together, I need to combine like terms first 12 I'll work with the X squares, which is negative two X squared, 13 plus three X squared, which is just positive X squared. 14 And since we want to look at what's in front of it, right, 15 the a that's in front of it, we can think about there being an 16 invisible one in front of it. And that will combine the Xs positive 17 X plus seven X. That's going to be eight X, 18 right. And then finally the normal numbers, 19 31 minus eight. That should give us 23, 20 but let's just double check here. Yep. 21 All right. And so now I just need to add the coefficients, 22 right? The a, which is here, the B, 23 which is here and the C, which is here. 24 So it's going to be 23 class eight plus one, 25 which is nine. And this will give us 32. 26 So then I add all the coefficients. My answer is 32.