1) Thực hiện phép tính (Tính nhanh nếu có thể)

a) 5.(-8).2.(-3)     

= (5.2).[-8.(-3) ]

= 10 . (-24)

= -240                                   

b)3.(-5)² +2.(-5)-20

=3.25+2.(-5)-20

=75+(-10)-20

=65-20

=45

c)34.(15-10)-15.(34-10)

=34.5-15.24

=170-360

=-190                          

d)27.(-17)+(-17).73

=-17.(27+73)

=-17.100

=-1700

e)512.(2-128)-128.(-512)

=512.(-126)-128.(-512)

=512.(-126)-(-128).512

=512.[-126-(-128)]

=512.2

=1024

a,\(5.\left(-8\right).2.\left(-3\right)\)                

\(=\left[\left(5.2\right).\left(-8\right).\left(-3\right)\right]\)

\(=10.24\)

\(=240\)

b,\(3.\left(-5\right)^2+2.\left(-5\right)-20\)

\(=3.25-2.\left(-5\right)-20\)

\(=75+10-20\)

\(=65\)

Bạn chỉ gửi 1 bài thôi chứ nhiều quá làm mỏi tay lắm

Làm bài 1 trước

\(4\cdot(-5)^2+2\cdot(-5)-20\)

\(=4\cdot25+2\cdot(-5)-20\)

\(=100+(-10)-20=100-30=70\)

\(35\cdot(14-10)-14\cdot(35-10)\)

\(=35\cdot14-35\cdot10-14\cdot35-14\cdot10\)

\(=35\cdot14-14\cdot35-35\cdot10-14\cdot10\)

\(=35\cdot10-14\cdot10=(35-14)\cdot10=210\)

\(3\cdot(-5)^2+2\cdot(-5)-20\)

Tương tự như ở câu trên

\(34\cdot(15-10)-15\cdot(34-10)\)

Tương tự như câu thứ 2

Câu cuối tự làm

d, 512. ( 2 - 128 ) - 128 . ( - 512 )

= 512 . ( - 126 ) - ( - 128 ) . 512

= 512. ( - 126 + 128 )

= 512. 2

= 1024

512 . ( 2 - 128 ) - 128 . ( -512 )

= 512 . -126 - 128 . 512

= 512 . ( -126 + 128 )

= 512 . 2

= 1024

Lm đủ tất thì mk ms nha !

512 x ( 2 - 128 ) - 128 x ( -512 )

= 512 x ( -126 ) - ( -128 ) x 512

= 512 x [ ( -126 ) - ( -128 ) ]

= 512 x 2

= 1024

512 × (2 - 128) - 128 × (-512)

= 512 × (-126) - (-128) × 512

= 512 × [(-126) - (-128)]

= 512 × 2

= 1024

= 1024 nha

   512.(2-128)-128.(-512)

= [512.(2-128)]-[128.(-512)

= - 64512 - (- 65536)

= - 64512 + 65536

= 1024

\(512.(2-128)-128.(-512)\)

\([512.(2-128)]-[128.(-512)]\)

\(-64512-(-65536)\)

\(-64512+65536\)

\(1024\)

512.[2-128]-128.[-512]

=512.[-126]-128.[-512]

=[-512].126-128.[-512]

=[-512].[126-128]

=[-512].[-2]

=11024

a) 13 . (-7) 

= -91

b) (-8) . (-25)

= 200

c) 25 . (-47) . (-4)

= -1175 . -4

= 4700

d) 512 . (2-128) - 128 . (-512)

= -64512 - -65536

= 1024

k mình nha

Chúc bạn học giỏi

Mình cảm ơn bạn nhiều

a)13.(-7)=-91

b)(-8).(-25)=200

c)25.(-47).(-4)=-1175.(-4)=4700

d)512.(2-128)-128.(-512)=512.(-126)-128.(-512)=-64512-128.(-512)=-64512-(-65536)=1024

\(11\div\left\{\frac{7}{8}-3\cdot\left[0,25\div\left(1\frac{1}{3}+2\cdot\frac{1}{3}\right)\right]\right\}\)

\(=11\div\left\{\frac{7}{8}-3\cdot\left[\frac{1}{4}\div\left(\frac{4}{3}+2\cdot\frac{1}{3}\right)\right]\right\}\)

\(=11\div\left\{\frac{7}{8}-3\cdot\left[\frac{1}{4}\div\left(\frac{4}{3}+\frac{2}{3}\right)\right]\right\}\)

\(=11\div\left\{\frac{7}{8}-3\cdot\left[\frac{1}{4}\div2\right]\right\}\)

\(=11\div\left\{\frac{7}{8}-3\cdot\frac{1}{8}\right\}\)

\(=11\div\left\{\frac{7}{8}-\frac{3}{8}\right\}\)

\(=11\div\frac{1}{2}\)

\(=22\)

b) 101*789 + 456*128 - 789 + 912*436

= 789*100 + 456*128 + 912*436

= 789*100 + 912*64 + 912*436

= 789*100 + 912*500

= 100*(789 + 912*5)

= 100*5349

= 534900

\(a)\)\(11\div\left\{\frac{7}{8}-3\times\left[0,25\div\left(1\frac{1}{3}+2\times\frac{1}{3}\right)\right]\right\}\)

\(=\)\(11\div\left\{\frac{7}{8}-3\times\left[\frac{1}{4}\div\left(\frac{4}{3}+\frac{2}{3}\right)\right]\right\}\)

\(=\)\(11\div\left\{\frac{7}{8}-3\times\left[\frac{1}{4}\div2\right]\right\}\)

\(=\)\(11\div\left\{\frac{7}{8}-3\times\left[\frac{1}{4}\times\frac{1}{2}\right]\right\}\)

\(=\)\(11\div\left\{\frac{7}{8}-3\times\frac{1}{8}\right\}\)

\(=\)\(11\div\left\{\frac{7}{8}-\frac{3}{8}\right\}\)

\(=\)\(11\div\frac{1}{2}\)

\(=\)\(22\)

\(b)\)\(101\times789+456\times128-789+912\times436\)

\(=\)\(79689+58368-789+397632\)

\(=\)\(534900\)

13 . ( - 7 ) = - 91

( - 8 ) . ( - 25 ) = 200

25 . ( - 47 ) . ( - 4 ) = ( - 100 ) . ( - 47 ) = 4700

8 . ( 125 - 3000 ) = 8 . 125 - 3000 = 1000 - 3000 = - 2000

512 . ( 2 - 128 ) - 128 . ( - 512 ) = 512 . ( 2 - 128 + 128 ) = 512 . 2 = 1024

13 x (-7) = -91

(-8) x (-25) = 200

25 x (-47) x (-4) = 4700

8 x (125 - 3000) = -23000

512 x (2 - 128) - 128 x (-512) = 1024

Nếu sai thì thôi

Học tốt!!!