a) 35 . 34 + 35 . 38 + 65 . 75 + 65 . 45
b) 39 . 8 + 60 . 2 + 21 . 8
c) 36 . 28 + 36 . 82 + 64 . 69 + 64 . 4
d) 123 . 1001
<<TÍNH NHANH GIÚP MÌNH NHA !!! >>
Tinh bang cách hợp lý nhất
A,39×8+60×2+21×8 b,12×53+53×172-53×84
C,35×34+35×86+65×75+65×67+65×45
D,36×28+36×82+64×69+64×41
a, 39 . 8 + 60 . 2 + 21 . 8
= 39 . 8 + 15 . 4 . 2 + 21 . 8
= 39 . 8 + 15 . 8 + 21 . 8
= 8 . ( 39 + 15 + 21 )
= 8 . 75
= 600
b, 12 . 53 + 53 . 172 - 53 . 84
= 53 . ( 12 + 172 - 84 )
= 53 . 100
= 5300
c, 35 . 34 + 35 . 86 + 65 . 75 + 65. 67 + 65.45
= 35 . ( 34 + 86 ) + 65 . ( 75 + 67 + 45 )
= 35 . 120 + 65 . 187
= 4200 + 12155
= 16355
d, 36 . 28 + 36 . 82 + 64 . 69 + 64 . 41
= 36 . ( 28 + 82 ) + 64 . ( 69 + 41 )
= 36 . 110 + 64 . 110
= 110 . ( 36 + 64 )
= 110 . 100
= 11000
a, 39 . 8 + 60 . 2 + 21 . 8
= 39 . 8 + 15 . 4 . 2 + 21 . 8
= 39 . 8 + 15 . 8 + 21 . 8
= 8 . ( 39 + 15 + 21 )
= 8 . 75
= 600
b, 12 . 53 + 53 . 172 - 53 . 84
= 53 . ( 12 + 172 - 84 )
= 53 . 100
= 5300
c, 35 . 34 + 35 . 86 + 65 . 75 + 65. 67 + 65.45
= 35 . ( 34 + 86 ) + 65 . ( 75 + 67 + 45 )
= 35 . 120 + 65 . 187
= 4200 + 12155
= 16355
d, 36 . 28 + 36 . 82 + 64 . 69 + 64 . 41
= 36 . ( 28 + 82 ) + 64 . ( 69 + 41 )
= 36 . 110 + 64 . 110
= 110 . ( 36 + 64 )
= 110 . 100
= 11000
Tính nhanh:
35 . 34+35 . 38+65 . 75+65 . 45
36 . 28+36 . 82+64 . 69+64 . 41
123 . 456+456 . 321 -256 . 444
Các bạn giúp mik ha!@
a, 35. 34+ 35. 36+ 66. 75+ 66. 45
b, 3. 25. 8+ 4. 37. 6+ 2. 38. 12
c, 36. 28+ 36. 82+ 64. 69+ 64. 41
d, 39. 8+ 60. 2+21.8
Tính hợp lí
A.35 x 34 + 35 x 38 + 65 x 75 + 65 x 45
B. 12x 53 + 53 x 172 - 53 x 84
C. 35 x 28 + 36 x 82 + 64 x 69 + 64 x 41
D. A = 1+2+3+...+100
E. B =17+19+...+101+103
G. D= 3x (12+13+14+15) + 3x(8+7+6+5)
A.35 x 34 + 35 x 38 + 65 x 75 + 65 x 45
Câu này không tính hợp lí được
B. 12x 53 + 53 x 172 - 53 x 84
= 53 x (12 + 172 - 84)
= 53 x 100
= 5300
C. 36 x 28 + 36 x 82 + 64 x 69 + 64 x 41
= 36 x (28+82) + 64 x (69+41)
= 36 x 110 + 64 x 110
= (36+64) x 110
= 100 x 110
= 11 000
D. A = 1+2+3+...+100
= (1+ 100) x 50
= 101 x 50
= 5050
E. B =17+19+...+101+103
= (103 +17) x [(103 - 17):2 + 1]
= 120 x 44
=5280
G. D= 3x (12+13+14+15) + 3x(8+7+6+5)
= 3 x (5+6+7+8+12+13+14+15)
= 3 x (20 x 4)
= 3 x 80
=240
a) 10320
b) 5300
c) 11000
d) 5050
e) 2460
g) 240
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50+51+52+53+54+56+57+58+59+60+61+62+63+64+65+66+67+68+69+70=?
1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17 * 18 * 19 * 20 * 21 * 22 * 23 * 24 * 25 * 26 * 27 * 28 * 29 * 30 * 31 * 32 * 33 * 34 * 35 * 36 * 37 * 38 * 39 * 40 * 41 * 42 * 43 * 44 * 45 * 46 * 47 * 48 * 49 * 50 * 51 * 52 * 53 * 54 * 55 * 56 * 57 * 58 * 59 * 60 * 61 * 62 * 63 * 64 * 65 * 66 * 67 * 68 * 69 * 70 * 71 * 72 * 73 * 74 * 75 * 76 * 77 * 78 * 79 * 80 * 81 * 82 * 83 * 84 * 85 * 86 * 87 * 88 * 89 * 90 * 91 * 92 * 93 * 94 * 95 * 96 * 97 * 98 * 99 * 100 bằng bao nhiêu?
Bài 1 :
36 . 28 + 69 . 69 + 36 . 82 + 65 . 41 - 110
700 : 25 = ; 84 : 7 ; 108 : 9 ; 15 . 28 ; 125 . 48
Bài 2 : Tính nhanh
a) 35 . 34 + 65 . 75 + 35 . 86 + 65 . 45
b) 2 . 25 . 8 + 4 . 37 . 6 + 2 . 38 . 12
c) 108 + 16 . 216 - 2 . 108
d) 65 . 3 . 130 + 15 . 65
a, 35 x 34 + 35 x 38 + 65 x 75 + 45 x 65
b, 39 x 8 + 60 x 2 + 21 x 8
c, 58 x 75 + 58 x 50 - 58 + 25
d, 125 x 98 - 125 x 46 - 52 x 25
a.35 x 34 + 35 x 38 + 65 x 75 + 45 x 65
= 35 x (34 + 38) + 65 x 75 + 65 x 45
= 35 x 72 + 65 x (75+45)
= 35 x 72 + 65 x 120
= 35 x 72 + 65 x (72 + 48)
= 35 x 72 + 65 x 72 + 65 x 48
= (35+65) x 72 + 65 x 48
= 100 x 72 + 65 x 48
= 7200 + 3120
= 10320
b.39 x 8 + 60 x 2 + 21 x 8
=39 x 8 + 15 x 4 x 2 +21 x 8
= 39 x 8 + 15 x 8 + 21 x 8
=(39 + 15 + 21) x 8
= 75 x 8
= 600
c.58 x 75 + 58 x 50 - 58 + 25
= 58 x 75 + 58 x 50 - 58 x 1 + 25
= 58 x(75+50-1)+25
= 58 x 124 + 25
= 7192 + 25
= 7217
d.125 x 98 - 125 x 46 - 52 x 25
= 25 x 5 x 98 - 25 x 5 x 46 - 25 x 52
= 25 x 490 - 25 x 230 - 25 x 52
= 25 x (490 - 230 - 52)
= 25 x 208
= 5200