a + 200 : 2 = 800
a + 100 = 800
A = 800 - 100
a = 700
b -12 × 27 = 925 : 5
b - 324 = 185
b = 185 + 324
b = 509
1000 - C = 325 × 4 + 28 ÷ 7
1000 - C = 1300 + 4
1000 - C = 1304
c = 1304 - 1000
C = 304
820 - d×3 = 22 × 10
820 - d×3= 220
d×3 = 820 - 220
d × 3 = 600
d = 600 : 3
d = 300
Succes
