Solve 9x + 5 = 140
The solution of 9x + 5 = 140 is x = 15.
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 5 from both sides:
- 3
Divide both sides by 9:
- 4
Check: put x = 15 back into the equation.
LaTeX source of the formulas on this page
\[ 9x + 5 = 140\ \Rightarrow\ x = 15 \]
\[ 9x + 5 = 140 \]
\[ 9x + 5 - 5 = 140 - 5 \ \Rightarrow\ 9x = 135 \]
\[ \frac{9x}{9} = \frac{135}{9} \ \Rightarrow\ x = 15 \]
\[ 9\cdot15 + 5 = 135 + 5 = 140 \checkmark \]Trying values of x in 9x + 5 = 140
| x | 9x + 5 | Equals 140? |
|---|---|---|
| 13 | 122 | no |
| 14 | 131 | no |
| 15 | 140 | yes |
| 16 | 149 | no |
| 17 | 158 | no |
Questions
What is x in 9x + 5 = 140?
The solution of 9x + 5 = 140 is x = 15.
How do you solve 9x + 5 = 140?
Subtract 5 from both sides to get 9x = 135, then divide both sides by 9 to get x = 15.
How do I check the answer?
Replace x by 15: 9(15) + 5 = 140, which is 140.