Solve 2x ā 9 = ā27
The solution of 2x ā 9 = ā27 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 9 to both sides:
- 3
Divide both sides by 2:
- 4
Check: put x = -9 back into the equation.
LaTeX source of the formulas on this page
\[ 2x - 9 = -27\ \Rightarrow\ x = -9 \]
\[ 2x - 9 = -27 \]
\[ 2x - 9 + 9 = -27 + 9 \ \Rightarrow\ 2x = -18 \]
\[ \frac{2x}{2} = \frac{-18}{2} \ \Rightarrow\ x = -9 \]
\[ 2\cdot(-9) - 9 = -18 - 9 = -27 \checkmark \]Trying values of x in 2x ā 9 = ā27
| x | 2x ā 9 | Equals -27? |
|---|---|---|
| -11 | -31 | no |
| -10 | -29 | no |
| -9 | -27 | yes |
| -8 | -25 | no |
| -7 | -23 | no |
Questions
What is x in 2x ā 9 = ā27?
The solution of 2x ā 9 = ā27 is x = -9.
How do you solve 2x ā 9 = ā27?
Add 9 to both sides to get 2x = -18, then divide both sides by 2 to get x = -9.
How do I check the answer?
Replace x by -9: 2(-9) ā 9 = -27, which is -27.