What are the solutions of the equation (x + 2) 2 - 2 (x + 2) - 15 = 0? Use u substitution to solve.

x = - 7 and x = 1

x = - 5 and x = 3

x = - 3 and x = 5

x = - 1 and x = 7

x = - 5 and x = 3

Working

(x+2) ^2-2 (x+2) - 15=0

On expanding;

x^2+4x+4-2x-19=0

Simplifying gives:

x^2+2x-15=0

This can be expanded to;

x^2+5x-3x-15=0

Factoring out;

x (x+5) - 3 (x+5) = 0

(x-3) (x+5) = 0

x=3 or x = - 5