Solve for both systems: y+9z=27 and z + 3y = 3

y+9z=27

y+9z-9z=27-9z

y=27-9z

z + 3y = 3

z + 3(27-9z) = 3

z + 3(27) (3)(-9z) = 3

z+81-27z=3

81-26z=3

81-26z-81=3-81

-26z=-78

-26z/-26=-78/-26

z=3

y=27-9z

y=27-9(3)

y=27-27=0