Solve 8x ā 5 = ā69
The solution of 8x ā 5 = ā69 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 5 to both sides:
- 3
Divide both sides by 8:
- 4
Check: put x = -8 back into the equation.
LaTeX source of the formulas on this page
\[ 8x - 5 = -69\ \Rightarrow\ x = -8 \]
\[ 8x - 5 = -69 \]
\[ 8x - 5 + 5 = -69 + 5 \ \Rightarrow\ 8x = -64 \]
\[ \frac{8x}{8} = \frac{-64}{8} \ \Rightarrow\ x = -8 \]
\[ 8\cdot(-8) - 5 = -64 - 5 = -69 \checkmark \]Trying values of x in 8x ā 5 = ā69
| x | 8x ā 5 | Equals -69? |
|---|---|---|
| -10 | -85 | no |
| -9 | -77 | no |
| -8 | -69 | yes |
| -7 | -61 | no |
| -6 | -53 | no |
Questions
What is x in 8x ā 5 = ā69?
The solution of 8x ā 5 = ā69 is x = -8.
How do you solve 8x ā 5 = ā69?
Add 5 to both sides to get 8x = -64, then divide both sides by 8 to get x = -8.
How do I check the answer?
Replace x by -8: 8(-8) ā 5 = -69, which is -69.