Consider this system of equations:
2/3x+3/5y=12 (equation a)
5/2y-3x=6 (equation b)
the expression that gives the value of x is:
the solution for the system of equations is:

2x/3+3y/5=12 and 5y/2-3x=6

10x/15+9y/15=12  and 5y/2-6x/2=6

10x+9y=180  and 5y-6x=12

5(10x+9y=180)-9(5y-6x=12)

50x+45y-45y+54x=900-108

104x=792

x=792/104

x=99/13

...

10x+9y=180, using x from above

990/13+9y=180

(990+117y)/13=180

990+117y=2340

117y=1350

y=1350/117

y=150/13

So the solution is the point (99/13, 150/13)