Question

Use f(x)=-4x+1, g(x)=x^2-8x+21, and h(x)=║9-3x║ for these equations.

Find g(-5)
Find g(x+4)
If f(x)=53, find x.

Answer 1

Explanation:

For each problem, plug in the values, then simplify.

g(x) = x² − 8x + 21

g(-5) = (-5)² − 8(-5) + 21

g(-5) = 25 + 40 + 21

g(-5) = 86

g(x) = x² − 8x + 21

g(x+4) = (x+4)² − 8(x+4) + 21

g(x+4) = x² + 8x + 16 − 8x − 32 + 21

g(x+4) = x² + 5

f(x) = -4x + 1

53 = -4x + 1

52 = -4x

x = -13