Answer:
![\huge\boxed{r=-1}](https://img.qammunity.org/2021/formulas/mathematics/high-school/esh2dyc1stshpfqe0e0lnjrbzaq6aka0qg.png)
Explanation:
To solve for this equation, our goal is to isolate the variable r on one side by reversing the equation.
We have the equation
. Let's simplify it.
Apply the distributive property on the right:
![25 + r = (-5 \cdot 2) + (84 \cdot -5) + 6r\\\\25+r = -10 - 40r + 6r](https://img.qammunity.org/2021/formulas/mathematics/high-school/xythc2s0igxxxw2o2uqv2dy4cp1v9mndbc.png)
Combine like terms:
![25 + r = -10 - 34r](https://img.qammunity.org/2021/formulas/mathematics/high-school/5zw6ggbt8n9s1rqw30lef80a091towprpn.png)
Add 34r to both sides:
![25 + r + 34r = -10 - 34r + 34r\\\\25 + 35r = -10](https://img.qammunity.org/2021/formulas/mathematics/high-school/bvo93g4e7b5l44c3xz0rqfi49zfpkowucr.png)
Add 10 to both sides:
![25 + 35r + 10 = -10 + 10\\\\35 + 35r = 0](https://img.qammunity.org/2021/formulas/mathematics/high-school/8yn1punlzqp4n2irbbno887z099ey4myjy.png)
Subtract 35 from both sides:
![35 + 35r - 35 = 0 - 35\\\\35r = -35](https://img.qammunity.org/2021/formulas/mathematics/high-school/ced8vtb68av2fs1c0s6udrpe4wx4b2keys.png)
Divide both sides by 35:
![35r / 35 = -35 / 35\\\\r = -1](https://img.qammunity.org/2021/formulas/mathematics/high-school/sf67x76uq2kqd9buh1j0bhf3pof6tcnm2z.png)
Hope this helped!