Question

103z+8z-z=990
29d-5d+d=750

Answer 1

$1) \: \: 103z + 8z - z = 990 \\ 110z = 990 \\ z = 9 \\ \\ 2) \: 29d - 5d + d = 750 \\ 25d = 750 \\ d = 30$

Answer 2

103z+8z-z=990

110z=990

z=9

29d-5d+d=750

25d=750

d=30