Solve 7x + 10 = 31
The solution of 7x + 10 = 31 is x = 3.
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 10 from both sides:
- 3
Divide both sides by 7:
- 4
Check: put x = 3 back into the equation.
LaTeX source of the formulas on this page
\[ 7x + 10 = 31\ \Rightarrow\ x = 3 \]
\[ 7x + 10 = 31 \]
\[ 7x + 10 - 10 = 31 - 10 \ \Rightarrow\ 7x = 21 \]
\[ \frac{7x}{7} = \frac{21}{7} \ \Rightarrow\ x = 3 \]
\[ 7\cdot3 + 10 = 21 + 10 = 31 \checkmark \]Trying values of x in 7x + 10 = 31
| x | 7x + 10 | Equals 31? |
|---|---|---|
| 1 | 17 | no |
| 2 | 24 | no |
| 3 | 31 | yes |
| 4 | 38 | no |
| 5 | 45 | no |
Questions
What is x in 7x + 10 = 31?
The solution of 7x + 10 = 31 is x = 3.
How do you solve 7x + 10 = 31?
Subtract 10 from both sides to get 7x = 21, then divide both sides by 7 to get x = 3.
How do I check the answer?
Replace x by 3: 7(3) + 10 = 31, which is 31.