if $s(x)=2 - x^{2}$ and $t(x)=3x$, which value is equivalent to $(scirc t)(-7)$?\n-439\n-141\n153\n443
if $s(x)=2 - x^{2}$ and $t(x)=3x$, which value is equivalent to $(scirc t)(-7)$?\n-439\n-141\n153\n443
Answer
Explanation:
Step1: Find $t(-7)$
$t(x)=3x$, so $t(-7)=3\times(-7)= - 21$
Step2: Find $(s\circ t)(-7)$
Since $(s\circ t)(-7)=s(t(-7))$, and $t(-7)=-21$, then $s(t(-7))=s(-21)$. Given $s(x)=2 - x^{2}$, substitute $x = - 21$ into $s(x)$: $s(-21)=2-(-21)^{2}=2 - 441=-439$
Answer:
-439