Solve 9x ā 2 = ā20
The solution of 9x ā 2 = ā20 is x = -2.
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 9:
- 4
Check: put x = -2 back into the equation.
LaTeX source of the formulas on this page
\[ 9x - 2 = -20\ \Rightarrow\ x = -2 \]
\[ 9x - 2 = -20 \]
\[ 9x - 2 + 2 = -20 + 2 \ \Rightarrow\ 9x = -18 \]
\[ \frac{9x}{9} = \frac{-18}{9} \ \Rightarrow\ x = -2 \]
\[ 9\cdot(-2) - 2 = -18 - 2 = -20 \checkmark \]Trying values of x in 9x ā 2 = ā20
| x | 9x ā 2 | Equals -20? |
|---|---|---|
| -4 | -38 | no |
| -3 | -29 | no |
| -2 | -20 | yes |
| -1 | -11 | no |
| 0 | -2 | no |
Questions
What is x in 9x ā 2 = ā20?
The solution of 9x ā 2 = ā20 is x = -2.
How do you solve 9x ā 2 = ā20?
Add 2 to both sides to get 9x = -18, then divide both sides by 9 to get x = -2.
How do I check the answer?
Replace x by -2: 9(-2) ā 2 = -20, which is -20.