Solve for both systems: 6z+5y=80 and 6z+2y=50

6z+2y=50

6z-6z+2y=50-6z

2y=50-6z

2y/2=50-6z/2

y=25-3z

6z+5y=80

6z+5(25-3z)=80

6z+5(25) (5)(-3z)=80

6z+125-15z=80

125-9z=80

125-9z-125=80-125

-9z=-45

-9z/-9=-45/-9

z=5

y=25-3z

y=25-3(5)

y=25-15=10