f(2x-3) and g(x+4)

Question

find the indicated value of f(x) or g(x) if f(x) = 3x-4 and g(x) = x^2 -1

Answer 1

f(x) = 3x - 4

 

For f(2x-3) just replace the x in f(x) with 2x-3:

 

f(2x-3) = 3(2x-3) - 4

    = 6x - 9 - 4

    = 6x - 13

 

g(x) = x² - 1

 

For g(x+4), just the replace the x in g(x) with x+4:

 

g(x+4) = (x+4)² - 1

    = x² + 8x + 16 -1

    = x² + 8x + 15