Question

Express x^2 + 4x - 7 in the form (x + a)^3 - b where a and b are integers

Answer 1

(x+2)² - 11

Explanation:

Regroup terms

x² + 4x - 7

(x² + 4x) - 7

Complete the square

 coefficient of x term: 4

 divide coefficient in half: 2

 square it: 2²

 use 2² to complete the square:

(x² + 4x) - 7 = (x² + 4x + 2²) - 2² - 7 = (x+2)² - 11