5x+10z=150 4x + 4z = 92

5x+10z=150

5x+10z-10z=150-10z

5x=150-10z

5x/5=150-10z/5

x=30-2z

4x + 4z = 92 sub in x

4(30-2z)+4z=92 solve for z

120-8z+4z=92

120-4z=92

120-120-4z=92-120

-4z=-28

-4z/-4=-28/-4

z=7

x=30-2z sub in z=7

x=30-2(7)

x=30-14

x=16