Question

Factorize: $x^2-7x+12$.

• A. $(x-3)(x-4)$
• B. $(x+3)(x-4)$
• C. $(x-3)(x+4)$
• D. $(x+3)(x+4)$

Answer 1

The correct option is A $(x-3)(x-4)$

We have to break up $7x$ in the given expression into two parts in such a way that their sum is $7x$ and the product of their coefficients is $12$.
$x^2-7x+12$
$=x^2-4x-3x+12$
$=x(x-4)-3(x-4)$
$=(x-3)(x-4)$

Thus, $x^2-7x+12$ can be factorised as $(x-3)(x-4)$.