Bjr,
3 * x/3 = 7
x/3 = 7 * 3
x/3 = 21
x = 21/3 = 7
5 * 4/x = 4
4/x = 20
x = 20/4 = 5
5/6x = 5
x = 5 * 6/5 = 30/5 = 6
6x = 5
x = 5/6
7/9 = 7 * 1/9
5 * 1/3 = (5 * 1)/(1 * 3) = 5/3.
