Question

Can someone tell me how to solve equations like these?
If f(x) = 2x + 1 and g(x) = −2x − 3, find (f + g)(−1).


Thank you :)

Answer 1

(f+g)(x) = f(x) + g(x)


(f+g)(x) = 2x + 1 + (-2x - 3)


(f+g)(x) = 2x + 1 - 2x - 3


(f+g)(x) = -2

Answer 2

Now plug in x = -1

Answer 3

The problem is I'm not understanding the first steps.

Answer 4

which steps

Answer 5

step 1? step 2? or something else

Answer 6

When given an equation like this,

If f(x) = 2x + 1 and g(x) = −2x − 3, find (f + g)(−1).

What does it mean: Find(f + g)(-1) I'm confused

I also see stuff like: Find g(f[4]) And it's really confusing.

Answer 7

(f + g)(-1) really means f(-1) + g(-1)

Answer 8

so (f + g)(x) turns into f(x) + g(x)

Answer 9

So it's saying: What is f and g times -1?

And g(f[-1])] is saying, what is f times -1

Then we have: g(f), and we solve that and we've solved for g(f[-])?

Answer 10

no, g(f(-1)) is a function composition

Answer 11

you basically evaluate f(-1) first

then you take the result of that and plug it into g(x)

Answer 12

ok thanks

Answer 13

np