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45 votes
45 votes
What is the solution to f(x) = -4 when f(x) = 3x + 5 ?

User Dandikas
by
2.9k points

2 Answers

11 votes
11 votes

Answer:

-7

Explanation:

To find the solution you'd have to plug in the -4 for every x you see but in this solution there is only one x so then you'd plug it in for that x. So then you'd have f(-4= 3(-4) + 5 and then you'd solve it. To solve it you would first multiply the 3 with the -4 because when something is in a parenthesis and there is a number beside with no sign that means you multiply. When you multiply you should get -12. After you get -12 you add 5 and your answer is -7.

When they give you an equation with an f(x) they sometimes give you inputs which you plug in to get your output. -4 was an input and -7 (your answer) is an output.
(hopefully you understood how i solved..)

User ZachP
by
3.1k points
17 votes
17 votes

Answer: x=-3

Explanation:

-4=3x+5

isolate x by moving all other variables to the right

-4-5=3x+5-5

-9=3x

x=-3

User Vulture
by
3.2k points