Question

Given that f(x) = 2x + 1 and g(x) = −5x + 2, solve for f(g(x)) when x = 3.

−91

−33

−25

35

Answer 1

Okay so we'll solve g(x) first.
g(3) = -5(3) + 2 [Substitute]

Answer 2

f(3)=2x+1

g(3)=-5x+2

Answer 3

g(3) = -15 + 2
g(3) = -13

Answer 4

yes @jcpd910 so solve the equation
now you have -13

Answer 5

g(3) will replace the x in f(x)

Answer 6

yes replace it easy i think @jenniferjuice gets it

Answer 7

Let's see if she can solve it now.

Answer 8

\(f(g(x)) = 2(-5x+2)+1\)

Answer 9

zzr0ck3r we are not giving out answers, we are helping people make their own.

Answer 10

lol tnx man, the 99 shuold tell you I have done this before....

Answer 11

I gave no answers. I showed how to compose the function...

Answer 12

I think you made it too easy. A lot of people don't understand how g(x) replaces the x in f(x) when you're solving for f(g(x))

Answer 13

But let's not bicker over petty problems. :D

Answer 14

well there are two ways of thinking about this.

One: find the answer to g(a) and pluf that into f(x)
Two: compose the function f(g(x)) then evaluate f(g(a)).

I like to make sure people see both options

Answer 15

I did not get 17. Can I see your work please?

Answer 16

f(g(x))=2(−5x+2)+1
=2(−5*3+2)+1
= 2(-2+2)+1
2(0+2)+1
0+2+1
3

Answer 17

-5*3 is not -2.

Answer 18

-25?

Answer 19

2(-5*3+2)+1
2(-15+2)+1

Answer 20

Does that help?

Answer 21

* means multiplied by.

Answer 22

-25?

Answer 23

You got it. :)