Answer:
Explanation:
To solve the equation, isolate the variable from one side of the equation.
-22=-40+r
First, switch sides.
![\Rightarrow: \sf{-40+r=-22}](https://img.qammunity.org/2021/formulas/mathematics/high-school/d78mpbnl1d26k6tr784ucle6pwhytklked.png)
Then, you add by 40 from both sides.
![\Longrightarrow: \sf{-40+r+40=-22+40}](https://img.qammunity.org/2021/formulas/mathematics/high-school/dt6bfa7r4sh7m4ozl1nmeaczjxrvf87r4n.png)
Solve.
Add or subtract the numbers from left to right.
![\Longrightarrow: \sf{-22+40=18}](https://img.qammunity.org/2021/formulas/mathematics/high-school/1hju2by4hf68fedwxhwa1vbcwx76cbjxih.png)
![\Longrightarrow: \boxed{\sf{r=18}}](https://img.qammunity.org/2021/formulas/mathematics/high-school/wnruzlpndx4es90auwm72i1mnf3kss2d59.png)
- Therefore, the correct answer is C. "r=18".
I hope this helps! Let me know if you have any questions.