[Video] Q6: 3x^2 - 5x +2 5x^2 -2x -6 which of the following is the sum of the two polynomials shown above?

Explanation for Question 6 From the Math (Calc) Section on the Official Sat Practice Test 3

Not for number six, we're looking for the sum of the two polynomials shown 2 above. And so this is kind of a form of question that I haven't 3 seen often on the sat. And so it might look a little foreign to 4 you as well, but what they really want to know here is if you 5 know how to combine like terms, 6 right? And so there's, you could write it this way. You could write it 7 is three X squared minus five X plus two plus 8 five, whoops, not three, five X squared, 9 minus two X minus six. And then from there you can see, 10 okay, I want to combine like terms. So my three X squared, 11 my five X squared go together, my negative five X and my negative two 12 X go together. And then my plus two and my minus six go together. 13 Um, and so if it was more familiar to you, 14 you could write it out the long way for addition, 15 but it works perfectly fine. 16 The way they've shown up here, kind of written like a, 17 um, systems of equations, because you can just add straight down because all 18 the like terms are already paired with one another, 19 right? So we just have three X squared plus five X square. 20 That's eight X squared, negative five X minus two X that's minus seven 21 X, and then plus two minus six, that's negative four. 22 And so we see that answer right here and answer choice C. 23 And so that's going to be our best answer. And all we really had 24 to do here was add down, like we were using the elimination method of 25 substitution, except really what we were doing here was combining like terms.