Factor the expression X² +4 x-21 o(x-3)(x+7) o(x-7)(x+3) • (x+2)(x - 11.5) o (x +11.5)(x-2)

(x-3)(x+7)
Explanations:The given expression is:
[tex]x^2+4x-21[/tex]This can be factorised as shown below:
[tex]\begin{gathered} x^2-3x\text{ + 7x - 21} \\ x\text{ (x - 3) + 7 (x - 3)} \\ (x\text{ - 3 ) ( x + 7)} \end{gathered}[/tex]The factorised expression is (x-3)(x+7)