Answer:
r = 8 2/3
Explanation:
3/5 (r-7)=1
3/5 * (r-7)=1
5/3 * 3/5 * (r-7)=1 * 5/3 ==> multiply both sides by 5/3 to remove the 3/5
from the left side of the equation and isolate r
1 * (r-7) = 5/3
r - 7 = 5/3 ==> simplify
r = 7 + 5/3 ==> add 7 on both sides to isolate r
r = 7 + 3/3 + 2/3 ==> simplify
r = 7 + 1 + 2/3
r = 8 + 2/3
r = 8 2/3