# Given #g(x) = 5x^2 - 4x# and #h(x) =sqrt(x - 7)# how do you find g(h(x))?

##### 1 Answer

Feb 28, 2016

#### Explanation:

# g(h(x)) = g(sqrt(x-7)) # Now substitute x =

#sqrt(x-7) " for x in g(x) "# hence:

#g(sqrt(x-7)) = 5(sqrt(x-7))^2 - 4(sqrt(x-7)) # now

# (sqrt(x-7))^2 = x-7 #

#rArr g(h(x)) = 5(x-7) -4(sqrt(x-7)) #

#= 5x - 35 - 4(sqrt(x-7))#