Solve for both systems: 10z+3y=85 and 2y + z = 17

2y + z = 17

2y-2y + z = 17-2y

z = 17-2y

10z+3y=85

10(17-2y)+3y=85

10(17) (10)(-2y)+3y=85

170-20y+3y=85

170-17y=85

170-17y-170=85-170

-17y=-85

-17y/-17=-85/-17

y=5

z = 17-2y

z = 17-2(5)

z = 17-10=7