Solve 7x ā 13 = ā76
The solution of 7x ā 13 = ā76 is x = -9.
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 13 to both sides:
- 3
Divide both sides by 7:
- 4
Check: put x = -9 back into the equation.
LaTeX source of the formulas on this page
\[ 7x - 13 = -76\ \Rightarrow\ x = -9 \]
\[ 7x - 13 = -76 \]
\[ 7x - 13 + 13 = -76 + 13 \ \Rightarrow\ 7x = -63 \]
\[ \frac{7x}{7} = \frac{-63}{7} \ \Rightarrow\ x = -9 \]
\[ 7\cdot(-9) - 13 = -63 - 13 = -76 \checkmark \]Trying values of x in 7x ā 13 = ā76
| x | 7x ā 13 | Equals -76? |
|---|---|---|
| -11 | -90 | no |
| -10 | -83 | no |
| -9 | -76 | yes |
| -8 | -69 | no |
| -7 | -62 | no |
Questions
What is x in 7x ā 13 = ā76?
The solution of 7x ā 13 = ā76 is x = -9.
How do you solve 7x ā 13 = ā76?
Add 13 to both sides to get 7x = -63, then divide both sides by 7 to get x = -9.
How do I check the answer?
Replace x by -9: 7(-9) ā 13 = -76, which is -76.