## anonymous one year ago If c(x) = 4x – 2 and d(x) = x2 + 5x, what is c(d(x))

1. anonymous

hey you again :D

2. Nnesha

ello same question :=)

3. anonymous

so just do the same thing?

4. Nnesha

yes right

5. anonymous

but x is already x so would it be 2x^2 + 5x^2 in the D function?

6. Nnesha

that would be the same so just replace x in c(x) function by d(x)

7. Nnesha

$\huge\rm c(\color{ReD}{d(x)}) = c(\color{Red}{x^2+5x}) =4\color{reD}{x}-2$

8. anonymous

so am i just simplifying x^2+5x=4x-2?

9. Nnesha

no you need to plug x^2+5x into the x c(x^2+5x) is same as c(d(x))

10. Nnesha

4x -2 ^^^ that x replace by x^2 +5x

11. anonymous

ohhh

12. anonymous

4x^2 + 3

13. Nnesha

mhm.. how did you get that ?

14. anonymous

4 and x^2 combine then 5-2

15. Nnesha

remember when multiply same bases we should add their exponents $\huge\rm x^m \times x^n = x^{m+n}$ and on't forget the parenthesis

16. Nnesha

it should be like this $\huge\rm 4(x^2+5x)-2$ distribute parentheses by 4 and then combine like terms

17. anonymous

ohh i forgot parentheses

18. anonymous

4x2+20x−2??

19. Nnesha

:=) right