John R. answered 05/17/13
If the equation is R = a*s/a + 5:
R = a*s/a + 5 Given
R = s + 5 Simplify the fraction
R - 5 = s Subtract 5 from each side
s = R - 5 Symmetric Property
If the equation is R = a*s/(a - 5):
R = a*s/(a - 5) Given
R(a - 5) = a*s Multiply both sides by a - 5
R(a - 5)/a = s Divide each side by a
s = R(a - 5)/a Symmetric Property