Answer:
(x + 2)² = 9
x = 1 or - 5
Step-by-step explanation:
x² + 4x - 5 = 0
Solving first using completing the square method
x² + 4x = 5
x² + 4x + (4/2)² = 5 + (4/2)²
x² + 4x + 2² = 5 + 2²
x² + 4x + 4 = 5 + 4
x² + 4x + 4 = 9
Factorise
x² + 2x + 2x + 4 = 9
x(x + 2) + 2(x + 2) = 9
(x + 2)(x + 2) = 9
(x + 2)² = 9
Square root both sides
√(x + 2)² = √9
x + 2 = ± 3
x + 2 = +3
x = 3 - 2
x = 1
x + 2 = -3
x = -3 - 2
x = -5
Hence, x = 1 or - 5
