a) 24.62+48.19

=24.62+24.2.19

=24.(62+2.19)

=24.(62+38)

=24.100=2400

b) 38+41+117+159+62

=(38+62)+(41+159)+117

=100+200+117

=417

c)42.53+47.156-47.114

=42.53+(47.156-47.114)

=42.53+47.(156-114)

=42.53+47.42

=42.(53+47)

=42.100

=4200

47 x 83 + 21 x 53 + 47 x 17 - 79 x 53

= 47 x (83 + 17) + 53 x (21 - 79)

= 47 x 100 + 53 x (-58)

= 4700 - 3074

= 1626

Chưa học số âm

\(47.83+21.53+47.17-79.53\)

\(=47.\left(83+17\right)+53.\left(79+21\right)\)

\(=47.100+53.100\)

\(=4700+5300\)

\(=10000\)

13,28 . 37 + 6,72.53+13,28.63+6.72.47

= 13,28 . (37 +63) + 6,72. (47+ 53)

= 13,28 . 100 + 6,72. 100

= 100 . (13,28 + 6,72)

= 100 . 20

= 2000

Tính nhanh lớp 3 

37+58+26+63-8+74

Các bạn giúp mình nhé 

13,28x37+6,72x53+13,28x63+6,72x47

=13,28 x 43,72 x 53 + 836,64 +315,84

=580,6016 x53+1152,48

=30771,8848+1152,48

=31924,3648

3) 124 + (-52) . 124 + (-124 ) . (-47)
= 124 + (-52) . 124 + 124 . 47
= 124 \(\left[\left(-52\right)+1+47\right]\)
= 124.(-3)
= -372

4) 53. (51 + 4) + 53. ( 49+96) + 53
= 53 . 55 + 53 . 145 + 53
= 53(55+145) + 53
= 53 . 200 + 53
= 10600 +53
= 10653

=126

=61

=145

=40

53 + 73 =126

63 - 2 =61

83 + 62 =145

73 - 33 =40

đã kb nha!

53+73=126

63-2=61

83+62=145

73-33=40

k mk nha 

47+58+83-29-17-53

= (47 - 17) + ( 83 - 53 ) + ( 58 - 29 )

=    30        +     30        +     29 

=            60     +     29 

=                89

co tien ko ban