\(12\cdot\left(-47\right)+12\cdot\left(-19\right)+\left(-66\right)\cdot88\)

\(=12\left(-47-19\right)+\left(-66\right)\cdot88\)

\(=-66\cdot12+88\cdot\left(-66\right)\)

\(=-66\left(12+88\right)\)

\(=-66\cdot100=-6600\)

Đáp Án

a)52:4x3+2x52

=13x3+2x52

=39+104

=143

b)5x42-18:32

=100-0.5625

=99.4375

của bạn nha

a) 2/9 - (1/20 + 2/9)

= 2/9 - 1/20 - 2/9

= (2/9 - 2/9) - 1/20

= 0 - 1/20

= -1/20

b) -3/14 + 2/13 + (-25/14) + (-15/13)

= (-3/14 - 25/14) + (2/13 - 15/13)

= -2 - 1

= -3

c) -3/11 + 11/8 - 3/8 + (-8/11)

= (-3/11 - 8/11) + (11/8 - 3/8)

= -1 + 1

= 0

d) 3/8 + (-1/4) - (7/12 - 1/6)

= 1/8 - 5/12

= -7/24

e) (1/3 + 12/67 + 13/41) - (79/67 - 28/41)

= 1/3 + 12/67 + 13/41 - 79/67 + 28/41

= 1/3 + (12/67 - 79/67) + (13/41 + 28/41)

= 1/3 - 1 + 1

= 1/3

câu C đề sai hay sao í

a)=(4.25).37

    =100.37

    =3700

b)=(132+868)+(763+237)+29

   =1000+1000+29

   =2029

c)=7²+[131-1.20]

  =49+[131-20]

  =49+111

  =160

\(\dfrac{4}{5}\)+\(\dfrac{-5}{4}\)=\(\dfrac{0}{4}\)

\(\dfrac{-1}{3}\)+\(\dfrac{2}{5}-\dfrac{5}{6}\)=\(\dfrac{-10}{30}+\dfrac{12}{30}-\dfrac{25}{30}\)=\(\dfrac{-23}{30}\)

\(\dfrac{2}{3}-\dfrac{5}{7}.\dfrac{14}{25}\)=\(\dfrac{2}{3}-\dfrac{2}{5}\)=\(\dfrac{10}{15}-\dfrac{6}{15}\)=\(\dfrac{4}{15}\)

a: \(=\dfrac{16-25}{20}=\dfrac{-9}{20}\)

b: \(=\dfrac{-10}{30}+\dfrac{12}{30}-\dfrac{25}{30}=-\dfrac{23}{30}\)

c: \(=\dfrac{2}{3}-\dfrac{1}{5}\cdot2=\dfrac{2}{3}-\dfrac{2}{5}=\dfrac{10-6}{15}=\dfrac{4}{15}\)

d: \(=\dfrac{12-25}{30}\cdot\dfrac{15}{8}-1=\dfrac{-13}{16}-1=\dfrac{-29}{16}\)

e: \(=\dfrac{-3}{13}-\dfrac{10}{13}-\dfrac{7}{17}+\dfrac{24}{17}-\dfrac{5}{19}-\dfrac{14}{19}=-1\)

Bài 2: Tính nhanh

a) 29 + 132 + 237 + 868 + 3

 = 29+(132+858)+(237+3)

=29+990+240

=1259

29+132+237+868+3

29+(132+868)+(237+3)

29+1000+240

29+(1000+240)

29+1240

1269

bài 2 :

a) 29 + 132 + 237 + 868 + 3

= 29 +(132 + 868)+(237 + 3)

= 29 + 1000 + 240

=1269

b) 35 . 34 + 35 . 86 + 65 . 75 + 65 . 5
= 35 .(34 + 86)+ 65 .(75 + 5)

= 35 . 120 + 65 . 80

= 4200 + 5200

= 9400

c) 3 . 25 . 8 + 4 . 37 . 6 + 2 . 38 .12

khum bít làm hehe

d) 12 . 53 + 53 . 172 - 53 . 84

= 53 . (12 + 172 - 84)

= 53 . 100

= 5300

Bài 3:

a) 4 . 52 - 18 : 32 hình như câu này sai đề

b) 32 . 22 - 32 . 19

= 32 . (22 - 19)

= 32 . 3

= 96

Bài 7: Thực hiện phép tính (tính hợp lí nếu có thể)

a) 78 349 – 10 240 + 56 711

= ( 78 349  + 56 711 ) – 10 240

=  635060 - 10240

=  624820

b) 234. 66 + 54. 80

=  15444 + 4320

= 19760

c) 13. 89 – 43. 17 + 339. 7

=  1157 - 731 + 2373

=  (1157 + 2373) - 731 

= 3530 - 731

=  2799

d) 2 085 – 1 196 : 26

=  2 085 – 46

=  2039

e) 214. 72 – 45. 214 – 214.27

= 214.( 72 – 45 – 27 )

= 214 . 0

= 0

\(a,=68109+56711=124820\)

\(b,=15444+4320=10764\)

\(c,1157-731+2373=426+2373=2799\)

\(d,=2085-46=2039\)

\(e,214.\left(72-45-27\right)=214.\left(-20\right)=-4200\)

\(g,=8327-1179=7148\)

\(h,=1225-1179=46\)

\(i,2304+1696=4000\)

\(k,=840+30+630=1500\)

\(m,456\left(123+321\right)-256=456.444-256=202464-256=202208\)

g) (4568 + 3759) – ( 4563 + 3754)

=  4568 + 3759 –  4563 - 3754

= ( 4568  - 4563 ) +( 3759 –3754)

= 5 + 5= 10

i)16 . 114 + 53 . 32

= 16 ( 114 + 53 . 2)

= 16 . 220

=  3520

k)15 . 56 + 30 + 42 . 15

= 15 ( 56 + 2 + 42)

= 15 . 100

=  1500

m) 123 . 456 + 456 . 321 – 256 . 

=   456  ( 123 + 321) - 256=

=  456 . 444 - 256

=  202464  - 256

=    202258