Solve 8x ā 3 = ā75
The solution of 8x ā 3 = ā75 is x = -9.
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 3 to both sides:
- 3
Divide both sides by 8:
- 4
Check: put x = -9 back into the equation.
LaTeX source of the formulas on this page
\[ 8x - 3 = -75\ \Rightarrow\ x = -9 \]
\[ 8x - 3 = -75 \]
\[ 8x - 3 + 3 = -75 + 3 \ \Rightarrow\ 8x = -72 \]
\[ \frac{8x}{8} = \frac{-72}{8} \ \Rightarrow\ x = -9 \]
\[ 8\cdot(-9) - 3 = -72 - 3 = -75 \checkmark \]Trying values of x in 8x ā 3 = ā75
| x | 8x ā 3 | Equals -75? |
|---|---|---|
| -11 | -91 | no |
| -10 | -83 | no |
| -9 | -75 | yes |
| -8 | -67 | no |
| -7 | -59 | no |
Questions
What is x in 8x ā 3 = ā75?
The solution of 8x ā 3 = ā75 is x = -9.
How do you solve 8x ā 3 = ā75?
Add 3 to both sides to get 8x = -72, then divide both sides by 8 to get x = -9.
How do I check the answer?
Replace x by -9: 8(-9) ā 3 = -75, which is -75.