Question

Solve 3(x-4)= 21.
A. x = 7
B. x = 9
C. x = 6
D. x = 11

Answer 1

The answer is D.

I will be explaining the simplest method of doing this first. The photo I have added is the longer method.

Step 1: Get rid of 3

We can do this by dividing both sides by 3.

3(x-4)/3=21/3

x-4 = 7

Step 2: Get rid of 4, so we can just have X.

We can do this by adding 4 on both sides.

x-4+4=7+4

x=11

Now you have your answer :)

Answer 2

D) 11

3(x-4)=21

3x-12=21

3x=21+12

3x=33

3x/3= 33/3

x=11