Solve 11x ā 1 = 87
The solution of 11x ā 1 = 87 is x = 8.
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 1 to both sides:
- 3
Divide both sides by 11:
- 4
Check: put x = 8 back into the equation.
LaTeX source of the formulas on this page
\[ 11x - 1 = 87\ \Rightarrow\ x = 8 \]
\[ 11x - 1 = 87 \]
\[ 11x - 1 + 1 = 87 + 1 \ \Rightarrow\ 11x = 88 \]
\[ \frac{11x}{11} = \frac{88}{11} \ \Rightarrow\ x = 8 \]
\[ 11\cdot8 - 1 = 88 - 1 = 87 \checkmark \]Trying values of x in 11x ā 1 = 87
| x | 11x ā 1 | Equals 87? |
|---|---|---|
| 6 | 65 | no |
| 7 | 76 | no |
| 8 | 87 | yes |
| 9 | 98 | no |
| 10 | 109 | no |
Questions
What is x in 11x ā 1 = 87?
The solution of 11x ā 1 = 87 is x = 8.
How do you solve 11x ā 1 = 87?
Add 1 to both sides to get 11x = 88, then divide both sides by 11 to get x = 8.
How do I check the answer?
Replace x by 8: 11(8) ā 1 = 87, which is 87.