If s(x) = 2 – x2 and t(x) = 3x, which value is equivalent to (s )? a. -439 b. -141 c. 153 d. 443

Option A -439

(s o t)(x)=s(t(x))
(s o t)(-7)=s(t(-7))
x=-7→t(-7)=3(-7)→t(-7)=-21
(s o t)(-7)=s(t(-7))=s(-21)
x=-21→s(-21)=2-(-21)^2=2-441→s(-21)=-439
(s o t)(-7)=s(t(-7))=s(-21)=-439
Option A -439

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.