Question

The roots of 7x^2 + x - 5 = 0 are a and b. Compute (a - 4)(b - 4).

Answer 1

Use FOIL (First, Outer, Inner, Last) to compute (a-4)(b-4)

(a-4)(b-4) =
ab - 4a - 4b + 16

Answer 2

just divide

Explanation:

and just use the formula