Tính hợp lí:
a) 5 . 11 . 18 + 9 . 31 . 10 + 4 . 29 . 45
b) 37 . 39 + 78 . 14 + 13 . 85 + 52 . 55
Mình cần gấp !
Tính hợp lí: | a) 5. 11. 18 + 9. 31. 10 + 4. 29. 45;b) 37. 39 + 78. 14 + 13. 85 + 52. 55. |
a: \(5\cdot11\cdot18+9\cdot31\cdot10+4\cdot29\cdot45\)
\(=11\cdot\left(5\cdot18\right)+31\cdot\left(9\cdot10\right)+29\cdot2\cdot\left(2\cdot45\right)\)
\(=90\left(11+31+29\cdot2\right)\)
\(=90\cdot100=9000\)
b: \(37\cdot39+78\cdot14+13\cdot85+52\cdot55\)
\(=37\cdot39+39\cdot2\cdot14+13\cdot85+13\cdot4\cdot55\)
\(=39\left(37+2\cdot14\right)+13\cdot\left(85+4\cdot55\right)\)
\(=39\cdot65+13\cdot305\)
\(=13\left(65\cdot3+305\right)=13\cdot500=6500\)
a)
5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45
=90.11+90.31+2.29.90=90.11+90.31+2.29.90
=90.(11+31+2.29)=90.(11+31+2.29)
=90.100=9000
b)
37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55
=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11
=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44
=39.65+65.(17+44)=39.65+65.(17+44)
=39.65+65.61=39.65+65.61
=65.(39+61)=65.(39+61)
=65.100=6500
a)
5.11.18+9.31.10+4.29.45
=90.11+90.31+2.29.90
=90.(11+31+2.29)
=90.100
=9000
b)
37.39+78.14+13.85+52.55
=37.39+39.2.14+13.5.17+13.4.5.11
=39.(37+2.14)+65.17+65.44
=39.65+65.(17+44)
=39.65+65.61
=65.(39+61)
=65.100
=6500
Tính hợp lí :
a= 39 x 118 +29 x 82
b = 37 x 39 + 78 x 14 + 13 x 85 + 52 x 55
c= 368 : 16 + 752 : 16 + 480 : 16
d= 5 x 11 x 18 + 9 x 31 x 10 + 4 x 29 x 45
a) \(39\times118+29\times82\)
\(=39\times2\times59+29\times2\times41\)
\(=2\times\left(39\times59+29\times41\right)\)
\(=2\times\left(2301+1189\right)\)
\(=2\times3490\)
\(=6980\)
b) \(37\times39+78\times14-13\times85-52\times55\)
\(=37\times3\times13+6\times13\times14+13\times85-4\times13\times55\)
\(=13\times\left(37\times3+6\times14+85-4\times55\right)\)
\(=13\times\left(111+84+85-220\right)\)
\(=13\times\left(280-220\right)\)
\(=13\times60\)
\(=780\)
c) \(368:16+752:16+480:16\)
\(=\left(368+752+480\right):16\)
\(=\left(1120+480\right):16\)
\(=1600:16\)
\(=100\)
d) \(5\times11\times18+9\times31\times10+4\times29\times45\)
\(=5\times11\times9\times2+9\times31\times10+2\times2\times29\times5\times9\)
\(=10\times9\times11+10\times9\times31+10\times29\times2\times9\)
\(=90\times11+90\times31+90\times29\times2\)
\(=90\times\left(11+31+29\times2\right)\)
\(=90\times\left(42+58\right)\)
\(=90\times100\)
\(=9000\)
Tính nhanh:
a) 5 x 11 x 18 + 9 x 31 x 10 + 4 x 29 x 45
b) 37 x 39 + 78 x 14 +13 x 85 + 52 x 55
c) ( 637 x 527 -189 ) : ( 526 x 637 + 448)
d) ( 1989 x 1990 + 3978 ) : ( 1992 x 1991 - 3984 )
e) 215 + 217 +219 + 221 +223
Mong mọi người giải hộ mình bài này với
Mọi người giải hộ bài này với
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?
45-5.(12+9)
24.(16-5)-16.(24-5)
29.(19-13)-19.(29-13)
31.(-18)+31.(-81)-31
(-12).47+(-12).52+(-12)
13.(23+22)-3.(17+28)
-48+48.(-78)+48.(-21)
Tính hợp lí !! Mk đag cần gấp lắm!!
Bn nào trả lời nhanh và sớm nhất mk sẽ cho 1 tích nha !! Thanks . ^_^ !!
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+149+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39*100
tính hợp lí :
35. 18 - 5.7.28
45 -5 . (12+9)
24.(16-5) - 16. (24-5)
29.(19-13) - 19. (29-13)
31.(-18) + 31.(-81) - 31
(-12).47 +(-12).52 + (-12)
13.(23+22) - 3.(17+28)
-48 + 48.(-78) + 48.(-21)
giải chi tiết thì mình tk cho nha
tính nhanh
25/37 x 18/29 + 18/29 x 12/37
31/85 x 11/19 + 31/85 x 12/19 - 42/19 x 31/85
c , 16/53 : 17/9 - 16/53 : 17/8
1/5 x 12/31 x 4/3 + 19/31 x 4/15
a) \(\dfrac{25}{37}\times\dfrac{18}{29}+\dfrac{18}{29}\times\dfrac{12}{37}\)
\(=\dfrac{18}{29}\times\left(\dfrac{25}{37}+\dfrac{12}{37}\right)\)
\(=\dfrac{18}{29}\times\dfrac{37}{37}\)
\(=\dfrac{18}{29}\times1\)
\(=\dfrac{18}{29}\)
b) \(\dfrac{31}{85}\times\dfrac{11}{19}+\dfrac{31}{85}\times\dfrac{12}{19}-\dfrac{42}{19}\times\dfrac{31}{85}\)
\(=\dfrac{31}{85}\times\left(\dfrac{11}{19}+\dfrac{12}{19}-\dfrac{42}{19}\right)\)
\(=\dfrac{31}{85}\times\dfrac{-19}{19}\)
\(=\dfrac{31}{85}\times-1\)
\(=-\dfrac{31}{85}\)
c) \(\dfrac{16}{53}:\dfrac{17}{9}-\dfrac{16}{53}:\dfrac{17}{8}\)
\(=\dfrac{16}{53}:\left(\dfrac{9}{17}-\dfrac{8}{17}\right)\)
\(=\dfrac{16}{53}:\dfrac{1}{17}\)
\(=\dfrac{16}{901}\)
c) \(\dfrac{1}{5}\times\dfrac{12}{31}\times\dfrac{4}{3}+\dfrac{19}{31}\times\dfrac{4}{15}\)
\(=\dfrac{4}{15}\times\dfrac{12}{31}+\dfrac{19}{31}\times\dfrac{4}{15}\)
\(=\dfrac{4}{15}\times\left(\dfrac{12}{31}+\dfrac{19}{31}\right)\)
\(=\dfrac{4}{15}\times\dfrac{31}{31}\)
\(=\dfrac{4}{15}\times1\)
\(=\dfrac{4}{15}\)
a: =18/29*(25/37+12/37)
=18/29
b: =31/85(11/19+12/19-42/19)
=-31/85
c; =16/53(9/17+8/17)=16/53
d: =4/15(12/31+19/31)=4/15