Mathematics for IGCSE & O level - Equations (Section 7 - No. 8)
What is the first step to solve the equation x² + 4x - 5 = 0 by factorization?
Use the quadratic formula.
Find two numbers that multiply to -5 and add to 4.
Set each factor to zero.
Move all terms to the right side.
Explication
Find two numbers whose product is the constant and sum equals the coefficient of x.