composition of functions problem

[TheNascar92]

I need help with this composition problem im pretty stuck i have:

f(x)= -x^2-2x (negative x squared minus 2 x)
g(x)=3x-1 (3x minus 1)

im supposed to compose f(g(x)). heres what i have done:

-(3x-1)^2-2(3x-1)=
-9x^2-6x+1-6x-2=
-9x^2-3 (negative 9x squared minus 3)

Are these steps correct? Can I leave the answer as it is or do i need to simplify??

 

[Mrspi]

I need help with this composition problem im pretty stuck i have:

f(x)= -x^2-2x (negative x squared minus 2 x)
g(x)=3x-1 (3x minus 1)

im supposed to compose f(g(x)). heres what i have done:

-(3x-1)^2-2(3x-1)=
-9x^2-6x+1-6x-2=
-9x^2-3 (negative 9x squared minus 3)

Are these steps correct? Can I leave the answer as it is or do i need to simplify??

You need to be careful about SIGNS.

-(3x - 1)[sup:3piu0zgz]2[/sup:3piu0zgz] - 2(3x - 1) = -(9x[sup:3piu0zgz]2[/sup:3piu0zgz] - 6x + 1) - 2(3x - 1)

or,
-(3x - 1)[sup:3piu0zgz]2[/sup:3piu0zgz] - 2(3x - 1) = -9x[sup:3piu0zgz]2[/sup:3piu0zgz] + 6x - 1 - 6x + 2

Simplify the right side by combining like terms.

 

[TheNascar92]

Awesome! thanks