Question

$x^2+5x-24$ can be factorized as .

• A. $(x-3)(x+8)$
• B. $(x-3)(x-8)$
• C. $(x+3)(x-8)$
• D. $(x+3)(x+8)$

Answer 1

The correct option is A $(x-3)(x+8)$

In order to factorize $x^2+5x-24$, we need to split the middle term $5x$ such that the sum or difference is 5 and product is -24.
Hence $5x$ is split as $-3x$ and $8x$.
$x^2-3x+8x-24$
$x(x-3)+8(x-3)$
Taking out $(x-3)$ common,
$x^2+5x-24$ = $(x-3)(x+8)$.