i need help on graphing each system and determining the number of solutions that it has. if it has one…

i need help on graphing each system and determining the number of solutions that it has. if it has one solution, name it. 1.y=2x y=6-x 2.y=x-3 y=-2x+9 3.x-y=4 x+y=10 4.2x+3y=4 2x+3y=-1