Question 484920
First, multiply both sides of equation two by 2 


-10x+4y=-30
5x-2y=15



-10x+4y=-30
2(5x-2y)=2(15)



-10x+4y=-30
10x-4y=30



Now add the equations to get 0 = 0



Since the equation is ALWAYS true, there are an infinite number of solutions.