Math: 0121a235

ID: 0121a235

(SAT Suite Question Bank > Find Questions > Assessment: SAT + Test: Math + Domain: Advanced Math)

Comment: Think of the table of coordinates in ordered pairs if it helps.

Method 1: The solutions of a quadratic function reveal the factor or factors of that function. If, for instance, the lone solution is -3, then (x + 3) must be a factor (to the perfect square (x + 3)^2 = 0), never mind multiplicities. Looking at the table, we see two solutions: (-1, 0) and (2, 0). Thus, (x + 1) and (x - 2) must be factors, and the correct answer is (D). Watch out for (0, -3), which is not a solution of the function, but simply represents the y-intercept.

Method 2: Use Desmos to graph each answer choice and look for the one that correctly models the zeroes from the table. 

The purple graph shows the two points of interest, so the correct answer is (D).

Method 3: You can examine the answer choices one by one to knock out those that do not corroborate known information from the table, namely that when x = -1 and 2, y = 0.

A. ((-1) - 3) = -4 and ((2) - 3) = -1 X

B.  ((-1) + 3) = 2 and ((2) + 3) = 5 X

C. ((-1) - 1)((-1) + 2) --> (-2)(1) = -2 and ((2) - 1)((2) + 2) --> (1)(4) = 4 X

D. ((-1) + 1)((-1) - 2) --> (0)(-3) = 0 and ((2) - 2)((2) + 2) --> (0)(4) = 0 √

Once again, the correct answer is (D).