21 / 56 = 3 / 8

в е р  н о.............

Выражение: 1/6+1/12+1/20+1/30+1/42+1/56

Ответ: 0.375

Решаем по действиям:
1. 1/6=(1//6)
2. 1/12=(1//12)
3. (1//6)+(1//12)=0.25
4. 1/20=0.05
1.00|2_0_ _
1_0_0_|0.05
0
5. 0.25+0.05=0.3
+0.25
_0_._0_5_
0.30
6. 1/30=(1//30)
7. 0.3+(1//30)=(1//3)
8. 1/42=(1//42)
9. (1//3)+(1//42)=(5//14)
10. 1/56=(1//56)
11. (5//14)+(1//56)=0.375

Решаем по шагам:
1. (1//6)+1/12+1/20+1/30+1/42+1/56
1.1. 1/6=(1//6)
2. (1//6)+(1//12)+1/20+1/30+1/42+1/56
2.1. 1/12=(1//12)
3. 0.25+1/20+1/30+1/42+1/56
3.1. (1//6)+(1//12)=0.25
4. 0.25+0.05+1/30+1/42+1/56
4.1. 1/20=0.05
1.00|2_0_ _
1_0_0_|0.05
0
5. 0.3+1/30+1/42+1/56
5.1. 0.25+0.05=0.3
+0.25
_0_._0_5_
0.30
6. 0.3+(1//30)+1/42+1/56
6.1. 1/30=(1//30)
7. (1//3)+1/42+1/56
7.1. 0.3+(1//30)=(1//3)
8. (1//3)+(1//42)+1/56
8.1. 1/42=(1//42)
9. (5//14)+1/56
9.1. (1//3)+(1//42)=(5//14)
10. (5//14)+(1//56)
10.1. 1/56=(1//56)
11. 0.375
11.1. (5//14)+(1//56)=0.375