Solve for both systems x+7z=126 and 2x + 4z = 82

x+7z=126

x+7z-7z=126-7z

x=126-7z

2x + 4z = 82

2(126-7z) + 4z = 82

2(126) (2)(-7z) + 4z = 82

252-14z+ 4z = 82

252-10z= 82

252-10z-252= 82-252

-10z=-170

-10z/-10=-170/-10

z=17

x=126-7z

x=126-7(17)

x=126-119=7