Răspuns:
1)
278 135 +223 789 =501924
proba-
501924-223789=278135
432 156 - 235 788 =196368
proba-
196368+235788=432156
644 588 : 28 =23021
proba-
23021×28=644588
8738 x 235 =2053430
proba-
2053430:235=8738
2)
( 56 x b- 3 658) x 5 = 6 630
56×b-3658=6630:5
56×b-3658=1326
56×b=1326+3658
56×b=4984
b=4984:56
b=89
3)
{[ 5:(2 x 3-1)+ 14]: 15+3:[1+2 x ( 45:15 - 2)]}: 2 = 1
{[5:(6-1)+14]:15+3:[1+2×(3-2)]}:2=1
[(5:5+14):15+3:(1+2×1)]:2=1
[(1+14):15+3:(1+2)]:2=1
(15:15+3:3):2=1
(1+1):2=1
2:2=1
1=1
ADEVARAT
4)
I cm dintr-un metru = 1/100
1 m=100 cm
6 dl dintr-un litru = 2/3
6 dl=0,6 l=6/10 l =2/3 l
20 minute dintr-o ora =1/3
1ora =60 min
I g dintr-un kilogram =1/1000
1000g =1kg
Explicație pas cu pas: