SAT | Test 5 Digital | Module 1 | Problem 26 - IN 30 SECONDS OR LESS

[@OverclockingCowboy]

We can also use the vertex equation. The vertex is at h = (7-3)/2 = 2. f(x) = a (x-h)^2 + k f(x) = a (x-2)^2 + k f(x) = ax^2 -4ax + (4a + k) From which we get b = -4a c = 4a + k Thus, a+b = -3a Hence, Choice A for a>1.

[@OverclockingCowboy]

Without knowing the sum of solutions, we can plug in the 2 points in the equation. 49a + 7b + c = 0 (for 7,0) 9a - 3b + c = 0 (for -3,0) Taking the difference 40a + 10b = 0 4a + b = 0 b = -4a We have a+b = -3a Since a > 1 a+b has to be less than -3 Thus, choice A