Question

The quadratic equation x^2 - 8x = -4 is rewritten in the form (x + p)^2 = q. when q is a constant. What is the value of p ?

Answer 1

-4

Explanation:

If you multiply out the square, you can see ...

(x +p)^2 = q

x^2 +2px +p^2 = q

The coefficient of the x-term is 2p, so ...

2p = -8

p = -8/2 = -4