1) 15x + 2$x+3y$ = 3$4x+y$ 15x + 2x + 6y = 12x + 3y
17x + 6y = 12x + 3y
17x - 12x = 3y - 6y
5x = -3y
x = -3y/5

2) 2$5x-y$ - 3y = 2 + 3$2x-y$ 10x - 2y - 3y = 2 + 6x - 3y
10x - 5y = 2 + 6x - 3y
10$-3y/5$ - 5y = 2 + 6$-3y/5$ - 3y
-6y - 5y = 2 - 18y/5 - 3y
-11y = 2 - 18y/5 - 3y
-11y = 2 - 18y/5 - 15y/5
-11y = 2 - 33y/5
-55y = 10 - 33y
-55y + 33y = 10
-22y = 10
y = -10/22
y = -5/11

Now we can substitute y in the first equation to find x:
x = -3$-5/11$/5
x = 15/11
x = 15/11

Therefore, the solution to the system of equations is:
x = 15/11
y = -5/11