In other words, x is some number such that
7/11 - x/3 = 24/55
Solve for x. Rewrite each fraction using a common denominator. In this case, it would be lcm(3, 11, 55) = 3×5×11 = 165. Then
7/11 = (7×15)/(11×15) = 105/165
x/3 = (x×55)/(3×55) = 55x/165
24/55 = (24×3)/(55×3) = 72/165
So we have
105/165 - 55x/165 = 72/165
(105 - 55x)/165 = 72/165
105 - 55x = 72
-55x = -33
x = (-33)/(-55) = (3×11)/(5×11) = 3/5
