Solve 8x ā 10 = ā42
The solution of 8x ā 10 = ā42 is x = -4.
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 10 to both sides:
- 3
Divide both sides by 8:
- 4
Check: put x = -4 back into the equation.
LaTeX source of the formulas on this page
\[ 8x - 10 = -42\ \Rightarrow\ x = -4 \]
\[ 8x - 10 = -42 \]
\[ 8x - 10 + 10 = -42 + 10 \ \Rightarrow\ 8x = -32 \]
\[ \frac{8x}{8} = \frac{-32}{8} \ \Rightarrow\ x = -4 \]
\[ 8\cdot(-4) - 10 = -32 - 10 = -42 \checkmark \]Trying values of x in 8x ā 10 = ā42
| x | 8x ā 10 | Equals -42? |
|---|---|---|
| -6 | -58 | no |
| -5 | -50 | no |
| -4 | -42 | yes |
| -3 | -34 | no |
| -2 | -26 | no |
Questions
What is x in 8x ā 10 = ā42?
The solution of 8x ā 10 = ā42 is x = -4.
How do you solve 8x ā 10 = ā42?
Add 10 to both sides to get 8x = -32, then divide both sides by 8 to get x = -4.
How do I check the answer?
Replace x by -4: 8(-4) ā 10 = -42, which is -42.