Solve 4x ā 2 = ā42
The solution of 4x ā 2 = ā42 is x = -10.
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 4:
- 4
Check: put x = -10 back into the equation.
LaTeX source of the formulas on this page
\[ 4x - 2 = -42\ \Rightarrow\ x = -10 \]
\[ 4x - 2 = -42 \]
\[ 4x - 2 + 2 = -42 + 2 \ \Rightarrow\ 4x = -40 \]
\[ \frac{4x}{4} = \frac{-40}{4} \ \Rightarrow\ x = -10 \]
\[ 4\cdot(-10) - 2 = -40 - 2 = -42 \checkmark \]Trying values of x in 4x ā 2 = ā42
| x | 4x ā 2 | Equals -42? |
|---|---|---|
| -12 | -50 | no |
| -11 | -46 | no |
| -10 | -42 | yes |
| -9 | -38 | no |
| -8 | -34 | no |
Questions
What is x in 4x ā 2 = ā42?
The solution of 4x ā 2 = ā42 is x = -10.
How do you solve 4x ā 2 = ā42?
Add 2 to both sides to get 4x = -40, then divide both sides by 4 to get x = -10.
How do I check the answer?
Replace x by -10: 4(-10) ā 2 = -42, which is -42.