Question

what must be added to each of the following expressions to make it a whole square

(i) 4x^2 - 12x + 7

(ii) 4x^2 - 20x + 20

Answer 1

since

(2x-3)^2 = 4x^2 - 12x + 9
(2x-5)^2 = 4x^2 - 20x + 25

it should be clear.