Solve for both systems 3x+3z=63 and 2x + z = 40

2x + z = 40

2x -2x+ z = 40-2x

z = 40-2x

3x+3z=63

3x+3(40-2x)=63

3x+3(40) (3)(-2x)=63

3x+120-6x=63

120-3x=63

120-3x-120=63-120

-3x=-57

-3x/-3=-57/-3

x=19

z = 40-2x

z = 40-2(19)

z = 40-38=2