Solve 10x + 1 = ā99
The solution of 10x + 1 = ā99 is x = -10.
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 1 from both sides:
- 3
Divide both sides by 10:
- 4
Check: put x = -10 back into the equation.
LaTeX source of the formulas on this page
\[ 10x + 1 = -99\ \Rightarrow\ x = -10 \]
\[ 10x + 1 = -99 \]
\[ 10x + 1 - 1 = -99 - 1 \ \Rightarrow\ 10x = -100 \]
\[ \frac{10x}{10} = \frac{-100}{10} \ \Rightarrow\ x = -10 \]
\[ 10\cdot(-10) + 1 = -100 + 1 = -99 \checkmark \]Trying values of x in 10x + 1 = ā99
| x | 10x + 1 | Equals -99? |
|---|---|---|
| -12 | -119 | no |
| -11 | -109 | no |
| -10 | -99 | yes |
| -9 | -89 | no |
| -8 | -79 | no |
Questions
What is x in 10x + 1 = ā99?
The solution of 10x + 1 = ā99 is x = -10.
How do you solve 10x + 1 = ā99?
Subtract 1 from both sides to get 10x = -100, then divide both sides by 10 to get x = -10.
How do I check the answer?
Replace x by -10: 10(-10) + 1 = -99, which is -99.