Question

given f(x)=x^2+x and h(x)=2x^2+2x-18 find the values of x such that f(x)=h(-x)​

Answer 1

Answer:

The values of $x$ for which $f(x)=h(-x)$ is $x=6$ or $x=-3$

Step-by-step explanation:

$f(x)=h(-x)$

⇒

$x^{2} +x=2(-x)^{2} +2(-x)-18\\\\x^{2} +x=2x^{2} -2x-18\\\\2x+x=2x^{2} -x^{2} -18\\\\3x=x^{2} -18\\\\x^{2} -3x-18=0$

we can find the value of $x$ by factorization method ,

$x^{2} -3x-18=(x-6)(x+3)$

(since the factors of $-18$, $(-6,3)$ gives the sum $-3$ )

therefore $x=6$ or $x=-3$.

thank you