Solve 4x ā 14 = ā42
The solution of 4x ā 14 = ā42 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 14 to both sides:
- 3
Divide both sides by 4:
- 4
Check: put x = -7 back into the equation.
LaTeX source of the formulas on this page
\[ 4x - 14 = -42\ \Rightarrow\ x = -7 \]
\[ 4x - 14 = -42 \]
\[ 4x - 14 + 14 = -42 + 14 \ \Rightarrow\ 4x = -28 \]
\[ \frac{4x}{4} = \frac{-28}{4} \ \Rightarrow\ x = -7 \]
\[ 4\cdot(-7) - 14 = -28 - 14 = -42 \checkmark \]Trying values of x in 4x ā 14 = ā42
| x | 4x ā 14 | Equals -42? |
|---|---|---|
| -9 | -50 | no |
| -8 | -46 | no |
| -7 | -42 | yes |
| -6 | -38 | no |
| -5 | -34 | no |
Questions
What is x in 4x ā 14 = ā42?
The solution of 4x ā 14 = ā42 is x = -7.
How do you solve 4x ā 14 = ā42?
Add 14 to both sides to get 4x = -28, then divide both sides by 4 to get x = -7.
How do I check the answer?
Replace x by -7: 4(-7) ā 14 = -42, which is -42.