Question

F s(x) = 2 – x2 and t(x) = 3x, which value is equivalent to (s*t)(-7)

Answer 1

S(x) = 2 - x²

t(x) = 3x

s(t(x)) = st(x)

s(t(x)) :

s(3x)

So in s(x) = 2 - x²,  to solve for s(3x) we replace x with 3x

s(x) = 2 - x²

s(3x) = 2 - (3x)²

          =  2 - 9x²

st(x) = 2 - 9x²

st(-7) = 2 - 9*(-7)(-7)

         = 2 - 9*49 = 2 - 441 = -439

st(-7) = -439