1/\(\left(-12\right)\cdot46-12\cdot54=\left(-12\right)\cdot46+\left(-12\right)\cdot54\)

\(=\left(-12\right)\cdot\left(46+54\right)=\left(-12\right)\cdot100=-1200\)

2/\(3784+23-3785-15=3785+22-3785-15\)

\(=22-15=7\)

3/\(\left(-8\right)\cdot25\cdot\left(-2\right)\cdot4\cdot\left(-5\right)\cdot125\)

\(=\left[\left(-8\right)\cdot125\right]\cdot\left[25\cdot4\right]\cdot\left[\left(-5\right)\cdot\left(-2\right)\right]\)

\(=\left(-1000\right)\cdot100\cdot10=-1000000\)

4/\(19\cdot25+9\cdot95+19\cdot30=19\cdot\left(25+30\right)+9\cdot95\)

\(=19\cdot55+9\cdot95=95\cdot11+9\cdot95=95\cdot\left(11+9\right)=20\cdot95=1900\)

5/\(\left(-50+19+143\right)-\left(-79+25+48\right)\)

\(=\left(-50\right)+19+143+79-25-48\)

\(=118\)

6/\(\left(-25\right)\cdot\left(75-45\right)-75\cdot\left(45-25\right)\)

\(=\left(-25\right)\cdot30+\left(-25\right)\cdot3\cdot20\)

\(=\left(-25\right)\cdot\left(30+60\right)=\left(-25\right)\cdot90=-2250\)

7/\(\left(-37-17\right)\cdot\left(-9\right)+35\left(-9-11\right)\)

\(=\left(-54\right)\cdot\left(-9\right)+35\cdot\left(-20\right)\)

\(=486+\left(-700\right)=-214\)

8/\(\left(187-23\right)-\left(20-180\right)\)

\(=187-23-20+180=324\)

9/\(512\cdot2-128\cdot\left(-512\right)\)

\(=512\cdot2+128\cdot512=512\cdot\left(2+128\right)\)

\(=512\cdot130=66560\)

10/\(17\cdot\left(-25\right)+25\cdot21\)

\(=17\cdot\left(-25\right)-\left(-25\right)\cdot21=\left(-25\right)\cdot\left(17-21\right)\)

\(=\left(-25\right)\cdot\left(-4\right)=100\)

Chúc bạn học tốt.

1) (-12).46-12.54

=12.(-46)-12.54

=12.(-46-54)

=12.(-100)=(-1200)

10) 17.(-25)+25.21

= (-17).25+25.21

=25.(-17+21)

=25.4=100

( Mik đọc lướt qua thì thấy hai bài này dễ nên làm, chứ mấy bài kia chưa suy nghĩ gì, bạn tự làm nốt nhé!)

uhm

áp dụng kiến thức tính nhanh ý

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=1275

=1275

=1245

a,25/100 +19/22+19/35+3/4+3/22+16/35

=(19/22+3/22)+(19/35+16/35)+(25/100+3/4)

=   22/22 + 35/35 + ( 1/4 + 3/4)

= 22/22 + 35/35 + 4/4

= 1 + 1 + 1

= 3

b, 2/5 : 4/7 - 2/5 : 2/3

=(2/5 - 2/5) : (4/7 : 2/3)

= 0 : 6/7

=0

tất cả các số kia là đều phần hết

a: \(\frac{5}{11}\times\frac{7}{25}+\frac{15}{11}\times\frac15\)

\(=\frac{7}{11\times5}+\frac{3}{11}=\frac{7+3\times5}{11\times5}=\frac{22}{55}=\frac25\)

b: \(\frac37\times\frac{25}{19}-\frac17\times\frac{18}{19}\)

\(=\frac{75}{7\times19}-\frac{18}{7\times19}=\frac{57}{7\times19}=\frac37\)

1935 - ( 46 + 1935 ) + 16

= 1935 - 46 - 1935 + 16 

= ( 1935 - 1935 ) + ( -46 + 16 ) 

= 0  +    -30 

= -30

357 - 1284 + 1280 - 1357 

= ( 357 - 1357 ) + ( 1284 - 1280)

= -1000              +    4

= -996

Xin lỗi nha.  Giờ mik bận rùi còn câu cuối cùng thì bn hãy dựa vào các bài mik làm để làm nha ! 

a) 1935 - ( 46 + 1935 ) + 16

= 1935 - 46 -1935 + 16

= ( 1935 - 1935 ) - (46 -16)

= 0 - 30

= -30

b) 357 -1284 +1280 - 1357

= ( 357 - 1357 ) - (1284 - 1280)

= -1000 - 4

=-1004

c)1 - 4 -7 + 10 + 13 - 16 -19 + 22 + 25

= 25

\(A=\dfrac{9}{8}-\dfrac{8}{9}+\dfrac{3}{24}+\dfrac{1}{4}-\dfrac{5}{16}+\dfrac{19}{25}-\dfrac{1}{9}+\dfrac{2}{25}-\dfrac{1}{81}\)

\(=\dfrac{9}{8}+\dfrac{1}{4}-\dfrac{5}{16}+\dfrac{1}{8}-\dfrac{8}{9}-\dfrac{1}{9}-\dfrac{1}{81}+\dfrac{19}{25}+\dfrac{2}{25}\)

\(=\dfrac{10}{8}+\dfrac{1}{4}-\dfrac{5}{16}-1-\dfrac{1}{81}+\dfrac{21}{25}\)

\(=\dfrac{20+4-5}{16}-\dfrac{82}{81}+\dfrac{21}{25}\)

\(=\dfrac{19}{16}-\dfrac{82}{81}+\dfrac{21}{25}\)

\(=\dfrac{32891}{16\cdot81\cdot25}\)

b: \(B=-\dfrac{1}{3}-\dfrac{8}{35}-\dfrac{2}{9}-\dfrac{1}{35}+\dfrac{4}{5}-\dfrac{4}{9}+\dfrac{3}{7}\)

\(=\dfrac{-1}{3}-\dfrac{2}{9}-\dfrac{4}{9}-\dfrac{8}{35}-\dfrac{1}{35}+\dfrac{4}{5}+\dfrac{3}{7}\)

\(=\dfrac{-3-2-4}{9}+\dfrac{-9}{35}+\dfrac{28+15}{35}\)

\(=-1+\dfrac{-9+43}{35}=-1+\dfrac{34}{35}=-\dfrac{1}{35}\)

45-58+(-45)+(+58)-3=45-58-45+58-3=(45-45)+(58-58)-3=-3

(-57)-(-12)+3-(-57)=-57+12+3+57=(-57+57)+12+3=15

-(-24)-(-30)+(-24)-30+8=24+30-24-30+8=(24-24)+(30-30)+8=8

-(-12)+(+19)-(+12)+8-19=12+19-12+8-19=(12-12)+(19-19)+8=8

47-(-53)+(-47)-(+53)=47+53-47-53=(47-47)+(53-53)=0

-(+28)+32-(-28)+(-34)=-28+32+28-34=(-28+28)-(34-32)=-2

15-(+72)+(-15)+(+72)=15-72-15+72=(15-15)+(72-72)=0

20-(+46)+(-25)-(-46)=20-46-25+46=(20-25)+(46-46)=-5

28-(-32)+(-28)-32+5=28+32-28-32+5=(28-28)+(32-32)+5=5

-75+(-49)+(+75)+49-12=-75-49+75+49-12=(-75+75)+(49-49)-12=-12

\(...=45-58-45+58-3=-3\)

\(...=-57+12+3+57=15\)

\(...=24+30-24-30+8=8\)

\(...=12+19-12+8-19=8\)

\(...=47+53-47-53=0\)

\(...=-28+32+28-34=-2\)

\(...=15-72-15+72=0\)

\(...=20-46-25+46=-5\)

\(=...28+32-28-32+5=5\)

\(...=-75-49+75+49-12=-12\)