Answer:
[tex] \boxed{ \bold{ \huge{ \boxed{ \sf{r = 6}}}}}[/tex]
Option C is the correct option.
Step-by-step explanation:
[tex] \sf{1 + 5r - 4r = 7}[/tex]
Collect like terms
[tex] \longrightarrow{ \sf{1 + r = 7}}[/tex]
Move 1 to right hand side and change it's sign
[tex] \longrightarrow{ \sf{r = 7 - 1}}[/tex]
Subtract 1 from 7
[tex] \longrightarrow{ \sf{r = 6}}[/tex]
Hope I helped!
Best regards! :D
