Solve 9x ā 7 = ā88
The solution of 9x ā 7 = ā88 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 7 to both sides:
- 3
Divide both sides by 9:
- 4
Check: put x = -9 back into the equation.
LaTeX source of the formulas on this page
\[ 9x - 7 = -88\ \Rightarrow\ x = -9 \]
\[ 9x - 7 = -88 \]
\[ 9x - 7 + 7 = -88 + 7 \ \Rightarrow\ 9x = -81 \]
\[ \frac{9x}{9} = \frac{-81}{9} \ \Rightarrow\ x = -9 \]
\[ 9\cdot(-9) - 7 = -81 - 7 = -88 \checkmark \]Trying values of x in 9x ā 7 = ā88
| x | 9x ā 7 | Equals -88? |
|---|---|---|
| -11 | -106 | no |
| -10 | -97 | no |
| -9 | -88 | yes |
| -8 | -79 | no |
| -7 | -70 | no |
Questions
What is x in 9x ā 7 = ā88?
The solution of 9x ā 7 = ā88 is x = -9.
How do you solve 9x ā 7 = ā88?
Add 7 to both sides to get 9x = -81, then divide both sides by 9 to get x = -9.
How do I check the answer?
Replace x by -9: 9(-9) ā 7 = -88, which is -88.