I need help please!!!

Part 1

Explanation:

We'll replace every copy of x with -3. Then use PEMDAS to simplify.

f(x) = -2x+7

f(-3) = -2(-3)+7

f(-3) = 6+7

f(-3) = 13

Part 2

Explanation:

We work backwards in a sense compared to what part 1 did. Instead of finding f(x) based on x, we determine what x must be for a given f(x).

We'll replace f(x) with 29 and solve for x like so

f(x) = -2x+7

29 = -2x+7

-2x+7 = 29

-2x = 29-7

-2x = 22

x = 22/(-2)

x = -11

Note how if you replaced x with -11, we'd get,

f(x) = -2x+7

f(-11) = -2(-11)+7

f(-11) = 22+7

f(-11) = 29

which helps confirm we have the correct answer.