+130555 I thimk you have this
s / 6 = 209 / s and both sides = 11
So....
s / 6 = 11 multiply both sides by 6 and s = 66 on the left side
209 / s = 11 we can rearrange as 209 / 11 = s = 19 and this is the value of s on the right ....check for yourself that :
66 / 6 = 209 / 19 = 11
