Question

If s(x) = x - 7 and t(x) = 4x2 – X + 3, which expression is equivalent to (tºs)(x)?

Answer 1

4x² - 57x + 206

Explanation:

To evaluate (t ￮ s)(x), substitute x = s(x) into t(x) , that is

t(x - 7)

= 4(x - 7)² - (x - 7) + 3 ← expand (x - 7)² using FOIL

= 4(x² - 14x + 49) - x + 7 + 3

= 4x² - 56x + 196 - x + 10 ← collect like terms )

= 4x² - 57x + 206