1)   29,37- (5,25+4,12)=29,37-9,37=20

2)   26(13+173-86)=26. 100=2600

 (10,38 + 12,58 + 14,68) - (0,38 + 4,68 + 2,58) 

= 37.64 - 7.64

= 30

Câu 11lam sao vậy 

`(10,38+12,58+14,68) - (0,38+0,68+2,58)`

`= 10,38+12,58+14,68- 0,38-0,68 - 2,58`

`= (10,38- 0,38) +(12,58- 2,58)+(14,68- 0,68)`

`= 10 + 10 + 14`

`=20+14`

`=34`

a) (10,38+12,58+14,68)-(0,38+4,68+2,58)

=10,38+12,58+14,68-0,38-4,68-2,58

=10+10+10

=30

b) 17,6-5,3+16,8-7,6+15,3-6,8

=10+10+10

=30

a) = 3,265 + 2,735 + 4,572 + 1,428 

= 6,000 + 6,000 

= 12,000

b) = 37,64 - 7, 64 

= 30

a: \(72,9\times99+72+0,9\)

\(=72,9\times99+72.9\)

\(=72,9\times\left(99+1\right)=72,9\times100=7290\)

b: 17,6-5,3+16,8-7,6+15,3-6,8

=(16,8-6,8)+(17,6-7,6)+(15,3-5,3)

=10+10+10

=30

c: \(\left(10,38+12,58+14,98\right)-\left(0,38+4,68+2,58\right)\)

=10,38-0,38+12,58-2,58+14,98-4,68

=10+10+10,3

=30,3

d: \(\left(7,5\times18,3+24,6\times8,3\right)\times\left(47\times11-4700\times0,1-47\right)\)

=\(\left(7,5\times18,3+24,6\times8,3\right)\times\left(47\times11-470-47\right)\)

=\(\left(7,5\times18,3+24,6\times8,3\right)\times47\times\left(11-10-1\right)\)

=0

tớ cx đang thắc mắc câu 2!!!!!hihi!!^_^