Solve 5x ā 5 = ā15
The solution of 5x ā 5 = ā15 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 5 to both sides:
- 3
Divide both sides by 5:
- 4
Check: put x = -2 back into the equation.
LaTeX source of the formulas on this page
\[ 5x - 5 = -15\ \Rightarrow\ x = -2 \]
\[ 5x - 5 = -15 \]
\[ 5x - 5 + 5 = -15 + 5 \ \Rightarrow\ 5x = -10 \]
\[ \frac{5x}{5} = \frac{-10}{5} \ \Rightarrow\ x = -2 \]
\[ 5\cdot(-2) - 5 = -10 - 5 = -15 \checkmark \]Trying values of x in 5x ā 5 = ā15
| x | 5x ā 5 | Equals -15? |
|---|---|---|
| -4 | -25 | no |
| -3 | -20 | no |
| -2 | -15 | yes |
| -1 | -10 | no |
| 0 | -5 | no |
Questions
What is x in 5x ā 5 = ā15?
The solution of 5x ā 5 = ā15 is x = -2.
How do you solve 5x ā 5 = ā15?
Add 5 to both sides to get 5x = -10, then divide both sides by 5 to get x = -2.
How do I check the answer?
Replace x by -2: 5(-2) ā 5 = -15, which is -15.