Question

Part 1 ) y = 2x +5 and y = (-1/2)x+5
This system only has one solution because of the lines they are perpendicular. Then there exist only on the point of intersection.

Part 2) y = 3x + 5 and y = 3x - 7 this system contains no solution because of the the lines they are parallel which means there is no point of intersection.

Part 3) y = 5x + 3 and y = 5x + 3 this system has infinitely solutions because it is the same equation.