2z+9x=67
2z+9x-9x=67-9x
2z=67-9x
2z/2=67-9x/2
z=33.5-4.5x
3z + 5x = 58
3(33.5-4.5x) + 5x = 58
3(33.5) (3)(-4.5x) + 5x = 58
100.5-13.5x + 5x = 58
100.5-8.5x= 58
100.5-8.5x-100.5= 58-100.5
-8.5x=-42.5
-8.5x/-8.5=-42.5/-8.5
x=5
z=33.5-4.5x
z=33.5-4.5(5)
z=33.5-22.5=11