Answer:
Step-by-step explanation:
the first method :
s(x) = 2 - x and f(x) = 3x
(s f) (-7) = s(-7) ×f(-7)
but : s(-7) = 2 - (-7) =2+7 = 9
f(-7) = 3(-7) = - 21
so : (s f) (-7) = (9)×(-21) = - 189
the second method :
calculate : (s f) (x) == s(x)×f(x) = (2-x) 3x = 6x - 3x²
(s f) (-7) = 6(-7) -3 (-7)² = - 42 -147 = -189
