Solve 3x ā 3 = ā30
The solution of 3x ā 3 = ā30 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 3:
- 4
Check: put x = -9 back into the equation.
LaTeX source of the formulas on this page
\[ 3x - 3 = -30\ \Rightarrow\ x = -9 \]
\[ 3x - 3 = -30 \]
\[ 3x - 3 + 3 = -30 + 3 \ \Rightarrow\ 3x = -27 \]
\[ \frac{3x}{3} = \frac{-27}{3} \ \Rightarrow\ x = -9 \]
\[ 3\cdot(-9) - 3 = -27 - 3 = -30 \checkmark \]Trying values of x in 3x ā 3 = ā30
| x | 3x ā 3 | Equals -30? |
|---|---|---|
| -11 | -36 | no |
| -10 | -33 | no |
| -9 | -30 | yes |
| -8 | -27 | no |
| -7 | -24 | no |
Questions
What is x in 3x ā 3 = ā30?
The solution of 3x ā 3 = ā30 is x = -9.
How do you solve 3x ā 3 = ā30?
Add 3 to both sides to get 3x = -27, then divide both sides by 3 to get x = -9.
How do I check the answer?
Replace x by -9: 3(-9) ā 3 = -30, which is -30.