Solve for both systems: 4z+12x=84 and 8z + 13x = 157

4z+12x=84

4z+12x-12x=84-12x

4z=84-12x

4z/4=84-12x/4

z=21-3x

8z + 13x = 157

8(21-3x) + 13x = 157

8(21) (8)(-3x) + 13x = 157

168-24x+ 13x = 157

168-11x= 157

168-11x-168= 157-168

-11x=-11

-11x/-11=-11/-11

x=1

z=21-3x

z=21-3(1)

z=21-3=18