I need help solving composite functions. I've been stuck on them.

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Question

I need help solving composite functions. I've been stuck on them.

http://prntscr.com/bqsq8b

luffingsails · Answer

Can we start with the first, f+g?

If f(x) = 4 and g(x) = 7, what do you think f + g would be?

mathguy5 · Answer

11?

luffingsails · Answer

Right! It is really that east.

So, when you are given f(x) = 6x-8 and g(x) = x+7... if you need f+g, just add them together.

luffingsails · Answer

$$f+g = (6x-8) + (x+7)$$
$$f+g = 6x-8+x+7=7x-1$$

luffingsails · Answer

Subtraction would be the same except for subtracting them instead of adding them.

luffingsails · Answer

Similar for the other operations. Are you okay with trying some of them?

mathguy5 · Answer

Thank you so much. It says find the domain of f+g. Do they mean the domain of the answer of f+g or the domain of the problem?

luffingsails · Answer

Right, so after you perform the addition, you would then figure out the domain of the new function you created.