Solve 5x + 12 = 102
The solution of 5x + 12 = 102 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 12 from both sides:
- 3
Divide both sides by 5:
- 4
Check: put x = 18 back into the equation.
LaTeX source of the formulas on this page
\[ 5x + 12 = 102\ \Rightarrow\ x = 18 \]
\[ 5x + 12 = 102 \]
\[ 5x + 12 - 12 = 102 - 12 \ \Rightarrow\ 5x = 90 \]
\[ \frac{5x}{5} = \frac{90}{5} \ \Rightarrow\ x = 18 \]
\[ 5\cdot18 + 12 = 90 + 12 = 102 \checkmark \]Trying values of x in 5x + 12 = 102
| x | 5x + 12 | Equals 102? |
|---|---|---|
| 16 | 92 | no |
| 17 | 97 | no |
| 18 | 102 | yes |
| 19 | 107 | no |
| 20 | 112 | no |
Questions
What is x in 5x + 12 = 102?
The solution of 5x + 12 = 102 is x = 18.
How do you solve 5x + 12 = 102?
Subtract 12 from both sides to get 5x = 90, then divide both sides by 5 to get x = 18.
How do I check the answer?
Replace x by 18: 5(18) + 12 = 102, which is 102.