Question 637456
Given:
(1) 12y = 5x + 3
(2) 20x = 2y - 12
Rearrange (2)
(2)' 2y = 20x + 12
Muliply (2)' by 6
(3) 12y = 120x +72
Set (3) equal to (1) and simplify
120x + 72 = 5x + 3
115x = -69
x = -69/115
x = -3*23/5*23
x = -3/5
Put x into (1) 
12y = 5*(-3/5) + 3
12y = -3 + 3
y = 0
Is (X,y) = (-3/5,0) correct? Let's see.
Use (2)
Is (20*(-3/5) = 2*0 -12)?
Is (-60/5 = -12)?
Is (-12=-12)? Yes
The answer is (-3/5,0)