Answer:
case 1
3x-7y=9
-4x+5y=1
using a graph tool
the solution is the point (-4,-3)------------------> one solution
case 2
y=6x-2
y=6x-4
two parallel lines
the system has no solution---------------> zero solution
case 3
-5x+y=10
-25x+5y=50
is the same line----------------> infinite solutions
