TL : 

a) 4 x 2145 = 8580                 7 x 853 = 5971

b) 40263 x 7 =281841            5 x 1326 = 6630

c) 23109 x 8 = 184872            9 x 1427 = 12843

~HT~

40263 x 7 = 281841

Đáp án D

23109 x 8 = 184872

`@Khóii`

\(x × ( 75 + 57 ) = 32604\)

\(x × 132 = 32604\)

\(x = 32604 : 132\)

\(x = 247\)

x * 75 + 57 * x = 32604

x * (75 + 57) = 32604

x * 132 = 32604

x = 32604 : 132 = 247

\(1357\times28+73\times1357-1357=1357\times\left(28+73-1\right)=1357\times100=135700\)

= 1357(28+73-1)
= 1357x100
= 135700

= 1357 x (28 + 73) - 1357

= 135700

 a)12 x 11 + 21 x 11 x 11 + 11 x 33

= ( 12 x 11 ) + ( 21 x 11 x 11 ) + ( 11 x 33 )

= 

= 

b)132x11-11x32-54x11

= ( 132 x 11 ) - ( 11 x 32 ) - ( 54 x 11 )

= 

\(a,=11\times\left(12+21+33\right)=11\times66=726\\ b,=11\times\left(132-32-54\right)=11\times46=506\\ c,=11\times\left(245+365\right)=11\times610=6710\\ d,=75\times\left(78+89+123\right)=75\times290=21750\\ e,=\left(2\times50\right)\times\left(250\times8\right)=100\times2000=200000\\ g,=1994\times\left(867+11\right)=1994\times878=1750732\)

a) 12 x 11 + 21 x 11 + 11 x 33

= 11 x ( 12 + 21 + 33)

= 11 x 66

= 726

b) 132 x 11 - 11 x 32 - 54 x 11

= 11 x ( 132 - 32 - 54)

= 11 x 46

= 506

c) 245 x 11 + 11 x 365

= 11 x ( 245 + 365 )

= 11 x 610 = 6710

d) 78 x 75 + 75 x 89 + 75 x 123

= 75 x ( 78 + 89 + 123)

= 75 x 290 = 21750

e) 2 x 250 x 50 x 8

= (2 x 50) x ( 250 x 8)

= 100 x 2000 = 200000

g) 1994 x 867 + 1994 x 11

= 1994 x ( 867 + 11)

= 1994 x 878 = 1750732