Solve 2x ā 2 = ā20
The solution of 2x ā 2 = ā20 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 2 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
\[ 2x - 2 = -20\ \Rightarrow\ x = -9 \]
\[ 2x - 2 = -20 \]
\[ 2x - 2 + 2 = -20 + 2 \ \Rightarrow\ 2x = -18 \]
\[ \frac{2x}{2} = \frac{-18}{2} \ \Rightarrow\ x = -9 \]
\[ 2\cdot(-9) - 2 = -18 - 2 = -20 \checkmark \]Trying values of x in 2x ā 2 = ā20
| x | 2x ā 2 | Equals -20? |
|---|---|---|
| -11 | -24 | no |
| -10 | -22 | no |
| -9 | -20 | yes |
| -8 | -18 | no |
| -7 | -16 | no |
Questions
What is x in 2x ā 2 = ā20?
The solution of 2x ā 2 = ā20 is x = -9.
How do you solve 2x ā 2 = ā20?
Add 2 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 2 = -20, which is -20.