Răspuns :
a=3175-820=2355
b=3146+5371=8517
c=9402-6305=3097
d=7000-4200=2800
5430-x=1500 5430-1500=x x=3930
5557+y=7872
y=7872-5557
y=2315
a+820 = 3175
a = 3175 - 820
a = 2355
7872
b - 5371 = 3146
b = 3146 + 5371
b = 8517
9402 - c = 6305
c = 9402 - 6305
c = 3097
4200 +d = 7000
d = 7000 - 4200
d = 2800
8000 - 2570 - x = 1500
5430 - x = 1500
x = 5430 - 1500 = 3930
3640 + 1917 + y = 7872
5557 +y = 7872
y = 7872 - 5557 = 2315
a = 3175 - 820
a = 2355
7872
b - 5371 = 3146
b = 3146 + 5371
b = 8517
9402 - c = 6305
c = 9402 - 6305
c = 3097
4200 +d = 7000
d = 7000 - 4200
d = 2800
8000 - 2570 - x = 1500
5430 - x = 1500
x = 5430 - 1500 = 3930
3640 + 1917 + y = 7872
5557 +y = 7872
y = 7872 - 5557 = 2315