Question

f c(x) = 4x – 2 and d(x) = x2 + 5x, what is (C o D)(x)?
A) 4x^3 + 18x^2 – 10x
B) x^2 + 9x – 2
C) 16x^2 + 4x – 6
D) 4x^2 + 20x – 2

Answer 1

$\bf \begin{cases} c(x)=4x-2\\\\ d(x)=x^2+5x \end{cases}\qquad thus \\\\\\ (c\circ d)(x)\implies \begin{array}{llll} c(x)=&4x-2\\\\ c[\ d(x)\ ]=&4(dx)-2\\\\ c[\ \boxed{x^2+5x}\ ]= &4(\boxed{x^2+5x})-2 \end{array}$

distribute and simplify