Question

3X+ 9 = 21
I need to find X

Answer 1

x = 4

Explanation:

Subtract 9 from both sides which gives 3x = 12 then divide each side by 3 and you get x = 4

Answer 2

• 
  `\Large\boxed{\sf{x=4}}`

Explanation:

You have to find the value of x, to isolate it on one side of the equation.

`\sf{3x+9=21}`

First, you have to subtract by 9 from both sides.

`\sf{3x+9-9=21-9}`

Solve.

Subtract.

21-9=12

Rewrite the problem down.

3x=12

Then, you divide by 3 from both sides.

3x/3=12/3

Solve.

Divide the numbers from left to right.

12/3=4

`\Longrightarrow: \boxed{\sf{x=4}}`

The answer should have a "positive sign".

• Therefore, the correct answer is x=4.

I hope this helps, let me know if you have any questions.