I'm really lost with these substitution problems everytime I try to solve it it comes out with a weird number and doesn't work when double checking. Thanks for your help! Also is there anyway to do this on a graphing calculator?

3x+5y=2

x+4y=-4

y=-3x+12

y=-7x-36

-6y+8x=36

x=4y+11

y=6x-5

y=-x+9