Answer:
r=[tex]-\frac{S}{L} +1[/tex]
Step-by-step explanation:
You would want to isolate the r by itself by doing all the opposite operations.
First, you can divide the L to get
1-r =[tex]\frac{S}{L}[/tex]
Next, move the 1 to the other side to get
-r=[tex]\frac{S}{L} -1[/tex]
Then, we would not want to keep the negative so, move it to the other side to get
r= [tex]-\frac{S}{L} +1[/tex]
(Note the 1 changed to a positive because we move the negative to the other side so, negative or negative 1 will be positive.
