Question 1004710
c(x)=4x-2


c(x)=4(x)-2


c(<font color=red>x</font>)=4(<font color=red>x</font>)-2


c(<font color=red>d(x)</font>)=4(<font color=red>d(x)</font>)-2 ... replace every x with d(x)


c(<font color=red>d(x)</font>)=4(<font color=red>x^2+5x</font>)-2 ... replace the d(x) on the right side with x^2+5x


c(<font color=red>d(x)</font>)=4*x^2+4*5x-2


c(d(x))=4x^2+20x-2