Question

given the definitions of f(x) and g(x) below find the value of g(f(1)).f (x)= -3x + 4 g(x)= x squared + 7x + 5

Answer 1

f(x) = -3x + 4

g(x) = x^2 + 7x + 5

g(f(x)) = put x = f(x) in equation g(x)

g(f(x)) = (-3x + 4)^2 + 7(-3x + 4) + 5

put x = 1

g(f(1)) = (-3(1) + 4)^2 + 7(-3(1) + 4) + 5

= (-3+4)^2 + 7(-3 + 4) + 5

= 1^2 + 7(1) + 5

= 1 + 7 + 5

= 13

so the answer is 13