Solve 5x ā 2 = ā42
The solution of 5x ā 2 = ā42 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 2 to both sides:
- 3
Divide both sides by 5:
- 4
Check: put x = -8 back into the equation.
LaTeX source of the formulas on this page
\[ 5x - 2 = -42\ \Rightarrow\ x = -8 \]
\[ 5x - 2 = -42 \]
\[ 5x - 2 + 2 = -42 + 2 \ \Rightarrow\ 5x = -40 \]
\[ \frac{5x}{5} = \frac{-40}{5} \ \Rightarrow\ x = -8 \]
\[ 5\cdot(-8) - 2 = -40 - 2 = -42 \checkmark \]Trying values of x in 5x ā 2 = ā42
| x | 5x ā 2 | Equals -42? |
|---|---|---|
| -10 | -52 | no |
| -9 | -47 | no |
| -8 | -42 | yes |
| -7 | -37 | no |
| -6 | -32 | no |
Questions
What is x in 5x ā 2 = ā42?
The solution of 5x ā 2 = ā42 is x = -8.
How do you solve 5x ā 2 = ā42?
Add 2 to both sides to get 5x = -40, then divide both sides by 5 to get x = -8.
How do I check the answer?
Replace x by -8: 5(-8) ā 2 = -42, which is -42.