Solve 2x ā 15 = ā1
The solution of 2x ā 15 = ā1 is x = 7.
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 15 to both sides:
- 3
Divide both sides by 2:
- 4
Check: put x = 7 back into the equation.
LaTeX source of the formulas on this page
\[ 2x - 15 = -1\ \Rightarrow\ x = 7 \]
\[ 2x - 15 = -1 \]
\[ 2x - 15 + 15 = -1 + 15 \ \Rightarrow\ 2x = 14 \]
\[ \frac{2x}{2} = \frac{14}{2} \ \Rightarrow\ x = 7 \]
\[ 2\cdot7 - 15 = 14 - 15 = -1 \checkmark \]Trying values of x in 2x ā 15 = ā1
| x | 2x ā 15 | Equals -1? |
|---|---|---|
| 5 | -5 | no |
| 6 | -3 | no |
| 7 | -1 | yes |
| 8 | 1 | no |
| 9 | 3 | no |
Questions
What is x in 2x ā 15 = ā1?
The solution of 2x ā 15 = ā1 is x = 7.
How do you solve 2x ā 15 = ā1?
Add 15 to both sides to get 2x = 14, then divide both sides by 2 to get x = 7.
How do I check the answer?
Replace x by 7: 2(7) ā 15 = -1, which is -1.