Answer Choices
{3, 6}
{2}
{3}
{6}
Explanation for Question 9 From the Math (No Calc) Section on the Official Sat Practice Test 4
Now for number nine, we're asked to solve for the solution set for the 2 equation. And an important thing to know here, 3 background information, right, is that solutions that basically means solve 4 for X, all the Xs that satisfy this equation. 5 And so we're told the A's too. So we're going to rewrite this equation, 6 plugging into for a, and then solve for X. 7 So I now have X minus two is equal to X minus four. 8 And you see what's really in our way, here is this radical, 9 the square root. And in order to get rid of a square root, 10 you have to square. So I'm going to square both sides. 11 That'll allow me to get rid of the square root. This will cancel with 12 the square. So I have X minus two. 13 And do I have X squared minus 16? 14 Do I square both of my numbers? 15 No. Right. This is not what I have. I need to actually foil out, 16 um, the, 17 the right side of my equation. Cause it's really X minus four times X 18 minus four. Right. And when I fill those out, 19 I get X squared minus eight X plus 16. 20 So now if I'm going to, um, you know, go any further, 21 we can notice, okay, I have a quadratic here. 22 So when I solve for X, I need to factor. But if I'm going 23 to factor, I need to move these two guys over here so that it's 24 set equal to zero. So I'll subtract X from both sides and add two 25 to both sides that way this and this will cancel. 26 I'll get zero is equal to something it'll be X squared, 27 minus nine X plus 18. Right? 28 And if I'm going to fac...