Solve 8x ā 7 = ā63
The solution of 8x ā 7 = ā63 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 7 to both sides:
- 3
Divide both sides by 8:
- 4
Check: put x = -7 back into the equation.
LaTeX source of the formulas on this page
\[ 8x - 7 = -63\ \Rightarrow\ x = -7 \]
\[ 8x - 7 = -63 \]
\[ 8x - 7 + 7 = -63 + 7 \ \Rightarrow\ 8x = -56 \]
\[ \frac{8x}{8} = \frac{-56}{8} \ \Rightarrow\ x = -7 \]
\[ 8\cdot(-7) - 7 = -56 - 7 = -63 \checkmark \]Trying values of x in 8x ā 7 = ā63
| x | 8x ā 7 | Equals -63? |
|---|---|---|
| -9 | -79 | no |
| -8 | -71 | no |
| -7 | -63 | yes |
| -6 | -55 | no |
| -5 | -47 | no |
Questions
What is x in 8x ā 7 = ā63?
The solution of 8x ā 7 = ā63 is x = -7.
How do you solve 8x ā 7 = ā63?
Add 7 to both sides to get 8x = -56, then divide both sides by 8 to get x = -7.
How do I check the answer?
Replace x by -7: 8(-7) ā 7 = -63, which is -63.