Solve 7x ā 10 = ā31
The solution of 7x ā 10 = ā31 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 subtraction, then the multiplication.
- 2
Add 10 to 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
\[ 7x - 10 = -31\ \Rightarrow\ x = -3 \]
\[ 7x - 10 = -31 \]
\[ 7x - 10 + 10 = -31 + 10 \ \Rightarrow\ 7x = -21 \]
\[ \frac{7x}{7} = \frac{-21}{7} \ \Rightarrow\ x = -3 \]
\[ 7\cdot(-3) - 10 = -21 - 10 = -31 \checkmark \]Trying values of x in 7x ā 10 = ā31
| x | 7x ā 10 | Equals -31? |
|---|---|---|
| -5 | -45 | no |
| -4 | -38 | no |
| -3 | -31 | yes |
| -2 | -24 | no |
| -1 | -17 | no |
Questions
What is x in 7x ā 10 = ā31?
The solution of 7x ā 10 = ā31 is x = -3.
How do you solve 7x ā 10 = ā31?
Add 10 to 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) ā 10 = -31, which is -31.