Solve 3x ā 4 = ā13
The solution of 3x ā 4 = ā13 is x = -3.
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 4 to both sides:
- 3
Divide both sides by 3:
- 4
Check: put x = -3 back into the equation.
LaTeX source of the formulas on this page
\[ 3x - 4 = -13\ \Rightarrow\ x = -3 \]
\[ 3x - 4 = -13 \]
\[ 3x - 4 + 4 = -13 + 4 \ \Rightarrow\ 3x = -9 \]
\[ \frac{3x}{3} = \frac{-9}{3} \ \Rightarrow\ x = -3 \]
\[ 3\cdot(-3) - 4 = -9 - 4 = -13 \checkmark \]Trying values of x in 3x ā 4 = ā13
| x | 3x ā 4 | Equals -13? |
|---|---|---|
| -5 | -19 | no |
| -4 | -16 | no |
| -3 | -13 | yes |
| -2 | -10 | no |
| -1 | -7 | no |
Questions
What is x in 3x ā 4 = ā13?
The solution of 3x ā 4 = ā13 is x = -3.
How do you solve 3x ā 4 = ā13?
Add 4 to both sides to get 3x = -9, then divide both sides by 3 to get x = -3.
How do I check the answer?
Replace x by -3: 3(-3) ā 4 = -13, which is -13.