Solve 11x ā 4 = ā81
The solution of 11x ā 4 = ā81 is x = -7.
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 4 to both sides:
- 3
Divide both sides by 11:
- 4
Check: put x = -7 back into the equation.
LaTeX source of the formulas on this page
\[ 11x - 4 = -81\ \Rightarrow\ x = -7 \]
\[ 11x - 4 = -81 \]
\[ 11x - 4 + 4 = -81 + 4 \ \Rightarrow\ 11x = -77 \]
\[ \frac{11x}{11} = \frac{-77}{11} \ \Rightarrow\ x = -7 \]
\[ 11\cdot(-7) - 4 = -77 - 4 = -81 \checkmark \]Trying values of x in 11x ā 4 = ā81
| x | 11x ā 4 | Equals -81? |
|---|---|---|
| -9 | -103 | no |
| -8 | -92 | no |
| -7 | -81 | yes |
| -6 | -70 | no |
| -5 | -59 | no |
Questions
What is x in 11x ā 4 = ā81?
The solution of 11x ā 4 = ā81 is x = -7.
How do you solve 11x ā 4 = ā81?
Add 4 to both sides to get 11x = -77, then divide both sides by 11 to get x = -7.
How do I check the answer?
Replace x by -7: 11(-7) ā 4 = -81, which is -81.