Solve 7x + 5 = 131
The solution of 7x + 5 = 131 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 5 from both sides:
- 3
Divide both sides by 7:
- 4
Check: put x = 18 back into the equation.
LaTeX source of the formulas on this page
\[ 7x + 5 = 131\ \Rightarrow\ x = 18 \]
\[ 7x + 5 = 131 \]
\[ 7x + 5 - 5 = 131 - 5 \ \Rightarrow\ 7x = 126 \]
\[ \frac{7x}{7} = \frac{126}{7} \ \Rightarrow\ x = 18 \]
\[ 7\cdot18 + 5 = 126 + 5 = 131 \checkmark \]Trying values of x in 7x + 5 = 131
| x | 7x + 5 | Equals 131? |
|---|---|---|
| 16 | 117 | no |
| 17 | 124 | no |
| 18 | 131 | yes |
| 19 | 138 | no |
| 20 | 145 | no |
Questions
What is x in 7x + 5 = 131?
The solution of 7x + 5 = 131 is x = 18.
How do you solve 7x + 5 = 131?
Subtract 5 from both sides to get 7x = 126, then divide both sides by 7 to get x = 18.
How do I check the answer?
Replace x by 18: 7(18) + 5 = 131, which is 131.