Given ƒ (x) = 3x + 9, find x when ƒ (x) = 21.

A) 3

B) 4

C) 7

D) 10

Question

Mathematics

Francis

29 July, 10:40

Given ƒ (x) = 3x + 9, find x when ƒ (x) = 21.

A) 3

B) 4

C) 7

D) 10

+1

Answers (2)

Know the Answer?

Jovanny Black · Answer 1

X=21

21-9=12

3x=12

12divided by 3=4

X=4. The answer is B

Clinton Vazquez · Answer 2

B

Step-by-step explanation:

Replacing f (x) with 21, this is the equation

21=3x+9

First, subtract 9 from each side of the equation to get:

12 = 3x

Next, divide each side by 3 to get:

4 = x

So the answer is B.

Given ƒ (x) = 3x + 9, find x when ƒ (x) = 21.A) 3B) 4C) 7D) 10

Given ƒ (x) = 3x + 9, find x when ƒ (x) = 21.

A) 3

B) 4

C) 7

D) 10