Solve 8x + 15 = 175
The solution of 8x + 15 = 175 is x = 20.
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 8:
- 4
Check: put x = 20 back into the equation.
LaTeX source of the formulas on this page
\[ 8x + 15 = 175\ \Rightarrow\ x = 20 \]
\[ 8x + 15 = 175 \]
\[ 8x + 15 - 15 = 175 - 15 \ \Rightarrow\ 8x = 160 \]
\[ \frac{8x}{8} = \frac{160}{8} \ \Rightarrow\ x = 20 \]
\[ 8\cdot20 + 15 = 160 + 15 = 175 \checkmark \]Trying values of x in 8x + 15 = 175
| x | 8x + 15 | Equals 175? |
|---|---|---|
| 18 | 159 | no |
| 19 | 167 | no |
| 20 | 175 | yes |
| 21 | 183 | no |
| 22 | 191 | no |
Questions
What is x in 8x + 15 = 175?
The solution of 8x + 15 = 175 is x = 20.
How do you solve 8x + 15 = 175?
Subtract 15 from both sides to get 8x = 160, then divide both sides by 8 to get x = 20.
How do I check the answer?
Replace x by 20: 8(20) + 15 = 175, which is 175.