Question

If $f\left(x\right)=x^2+4x-12$, what are the zeros of $f$?

• A. $\{-6,2\}$
• B. $\{6,2\}$
• C. $\{3,2\}$
• D. $\{-3,-2\}$

Answer 1

Answer: (A)

$\{-6,2\}$

Given that:

$f\left(x\right)=x^2+4x-12$

Solution:

$f\left(x\right)=x^2+4x-12$

$f\left(x\right)=x^2+6x-2x-12$

$f\left(x\right)=x(x+6)-2(x+6)$

$f\left(x\right)=(x+6)(x-2)$

So, zeroes of $f\left(x\right)=-6$ or $2$ $=\{-6,2\}$

$A$ the correct option.