Question

help??
Composite functions:
If F(x)=3x+1 and g(x)=xˆ2+2x, find x when F(g(x)) = 10

Answer 1

F(x)=3x+1
g(x)=xˆ2+2x
f(g(x))=f(x^2+2x) =3(x^2+2x)+1
now
3(x^2+2x)+1=10
solve for x
3(x^2+2x)=9
simplify by 3
and
solve for x

Answer 2

(x^2+2x)=3
x^2+2x-3=0

(x-1) (x+3) =0
-1+3=2
-1*3=-3
can you go on ?

Answer 3

um I'm confused at the part where you put -1+3=2

Answer 4

(x-a)(x-b)=
x^2 -(a+b)x +(-a)(-b)

Answer 5

oooh yeah ok so my final answer is -3?