Solve 9x + 15 = 6
The solution of 9x + 15 = 6 is x = -1.
How to work it out
- 1
The goal is to get x alone. Undo the operations in the opposite order: first the addition, then the multiplication.
- 2
Subtract 15 from both sides:
- 3
Divide both sides by 9:
- 4
Check: put x = -1 back into the equation.
LaTeX source of the formulas on this page
\[ 9x + 15 = 6\ \Rightarrow\ x = -1 \]
\[ 9x + 15 = 6 \]
\[ 9x + 15 - 15 = 6 - 15 \ \Rightarrow\ 9x = -9 \]
\[ \frac{9x}{9} = \frac{-9}{9} \ \Rightarrow\ x = -1 \]
\[ 9\cdot(-1) + 15 = -9 + 15 = 6 \checkmark \]Trying values of x in 9x + 15 = 6
| x | 9x + 15 | Equals 6? |
|---|---|---|
| -3 | -12 | no |
| -2 | -3 | no |
| -1 | 6 | yes |
| 0 | 15 | no |
| 1 | 24 | no |
Questions
What is x in 9x + 15 = 6?
The solution of 9x + 15 = 6 is x = -1.
How do you solve 9x + 15 = 6?
Subtract 15 from both sides to get 9x = -9, then divide both sides by 9 to get x = -1.
How do I check the answer?
Replace x by -1: 9(-1) + 15 = 6, which is 6.