Solve 12x + 4 = 220
The solution of 12x + 4 = 220 is x = 18.
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 12:
- 4
Check: put x = 18 back into the equation.
LaTeX source of the formulas on this page
\[ 12x + 4 = 220\ \Rightarrow\ x = 18 \]
\[ 12x + 4 = 220 \]
\[ 12x + 4 - 4 = 220 - 4 \ \Rightarrow\ 12x = 216 \]
\[ \frac{12x}{12} = \frac{216}{12} \ \Rightarrow\ x = 18 \]
\[ 12\cdot18 + 4 = 216 + 4 = 220 \checkmark \]Trying values of x in 12x + 4 = 220
| x | 12x + 4 | Equals 220? |
|---|---|---|
| 16 | 196 | no |
| 17 | 208 | no |
| 18 | 220 | yes |
| 19 | 232 | no |
| 20 | 244 | no |
Questions
What is x in 12x + 4 = 220?
The solution of 12x + 4 = 220 is x = 18.
How do you solve 12x + 4 = 220?
Subtract 4 from both sides to get 12x = 216, then divide both sides by 12 to get x = 18.
How do I check the answer?
Replace x by 18: 12(18) + 4 = 220, which is 220.