1000 - d x 2 - 25 x 4 = 800
1000-d x 2- 100=800/+1000
D x 2 -100=1800/+100
d x 2=1900/ :2
d=850
e - 40 : 2 + 29 x 4=132
e-20+116=132/-116
e-20=16/+20
e=36
