Explanation for Question 11 From the Math (No Calc) Section on the 2017 October Sat
Question 11 says which of the following represents all the possible values of X 2 that satisfy the equation above. So to start solving for X, 3 I'm going to cross multiply, which means I'm going to multiply the denominator of 4 one side of the equation by the numerator of the other. 5 And I'm going to set those equal to each other. So two X times 6 X minus three is equal to two times X. 7 Then I'm going to factor this out. 8 So this becomes two X squared plus negative six X is equal 9 to two X, and then I'm going to move everything to the left side 10 of the equation by subtracting two X from both sides. 11 And this becomes two X squared plus negative eight X is equal 12 to zero. Now I need to factor to find what X is equal to. 13 So the first thing I'm going to do is factor out an X. 14 And that gives me two X minus eight times X is equal to zero, 15 which means that X is equal to zero and two X minus eight equals 16 zero. So we know that one of the values of X is zero 17 and therefore we can multiply C and D. Well, 18 we still need to sell for ax on the right side here. 19 So I'm going to add eight to both sides to get to X is 20 equal to eight. And then I'm going to divide both sides by two, 21 which gives me X is equal to four and X is equal 22 to zero. So I know that the correct answer is B.