Answer Choices
x = -2 += sqrt(2)
x = -2 += sqrt(30)/3
x = −6 ± sqrt(2)
x = −6 ± 6 sqrt(2)
Explanation for Question 14 From the Math (No Calc) Section on the Official Sat Practice Test 3
Not for number 14, we're asked what are the solutions to this expression, 2 right? And so you can see that we have something that has a plus 3 minus and all very answer choices, 4 and it has the radical. And so that's a clue that they don't really 5 want you to factor here what they want you to use as the quadratic 6 formula, which says the X is equal to opposite B plus or minus square 7 root of B squared, minus four, AC all over to a right. 8 And so our a is going to be three R B B's 12, 9 and our C is six. So we'll just plug and check now put in 10 our numbers for what variables they have and then simplify. 11 So negative B is negative 12 plus or minus the square root of 12 12 square, um, 13 minus four times and a of three times the C of six. 14 So all of that is square rooted all over two times three. 15 So negative 12, right? We know that two times three is six, 16 so we can simplify that right off the bat. And now we can work 17 with the radical, which is the square root of 12 squared, 18 1 44 minus four times three, 19 which is 12. So we're working with 12 times six, 20 which is 72. So the square root of 1 44 minus 72. 21 So we'll do that over here as well. It's looking like 72, 22 right? So we've got negative 12 plus or minus the square root of 72 23 Oliver six, but we can probably simplify the square root of 72, 24 right. Because 72, I believe that is yeah. 25 Six times 12. Is that useful for us? 26 Let's see if we can divide 72 by four. 27 Well, actually we'll, we'll...