Solve 2x + 4 = 30
The solution of 2x + 4 = 30 is x = 13.
How to work it out
- 1
The goal is to get x alone. Undo the operations in the opposite order: first the addition, then the multiplication.
- 2
Subtract 4 from both sides:
- 3
Divide both sides by 2:
- 4
Check: put x = 13 back into the equation.
LaTeX source of the formulas on this page
\[ 2x + 4 = 30\ \Rightarrow\ x = 13 \]
\[ 2x + 4 = 30 \]
\[ 2x + 4 - 4 = 30 - 4 \ \Rightarrow\ 2x = 26 \]
\[ \frac{2x}{2} = \frac{26}{2} \ \Rightarrow\ x = 13 \]
\[ 2\cdot13 + 4 = 26 + 4 = 30 \checkmark \]Trying values of x in 2x + 4 = 30
| x | 2x + 4 | Equals 30? |
|---|---|---|
| 11 | 26 | no |
| 12 | 28 | no |
| 13 | 30 | yes |
| 14 | 32 | no |
| 15 | 34 | no |
Questions
What is x in 2x + 4 = 30?
The solution of 2x + 4 = 30 is x = 13.
How do you solve 2x + 4 = 30?
Subtract 4 from both sides to get 2x = 26, then divide both sides by 2 to get x = 13.
How do I check the answer?
Replace x by 13: 2(13) + 4 = 30, which is 30.