Question

S=L-rL solve for r how do you solve this equation

Answer 1

These problems are called literal equations(just so you know)
S=L-rL
First, you subtract L from both sides:
S-L=-rL
The commutative property of multiplication states that you can change the order of 2 different numbers being multiplied together and still keep the equation/expression equivalent to the first. We can change r and L around like this:
S-L=-Lr
now we divide both sides by -L:

`(S-L)/(-L) =r`
We can still simplify this, though, by splitting up the fraction on the left:

`(S)/(-L) - (L)/(-L) =r`
which is equal to:

`(S)/(-L) -(-1)=r`
for the final step, the double negative becomes a positive:

`(S)/(-L) +1=r`
there is the final simplified answer for r