Solve the quadratic equation $x^2+7x+12=0$ by factorisation.

Step-by-step solution

1. Write the quadratic as a product of two linear factors: $x^2+7x+12=(x+3)(x+4)$ because $3\times 4=12$ and $3+4=7$.
2. Set each factor equal to zero: $x+3=0$ and $x+4=0$.
3. Solve the simple equations: $x=-3$ and $x=-4$.

Concept tested: Factorisation of quadratics

Published 22 August 2026 · How this solution was prepared and checked

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