x * 257 + x = 4644

x * 257 + x * 1 = 4644

x * (257 + 1)    = 4644

x * 258            = 4644

x                     = 4644 : 258

x                     = 18

Bạn ơi ghi đề sai nha ban phải là: 257 x 135 - 34 x 257 - 257 nha

257 x 135 - 34 x 257 - 257 x 1

= 257 x ( 135 - 34 -1 )

= 257 x 100

=25700

257 x 432 + 257 x 354 + 257 x 214

= 257 x ( 432 + 354 + 214 )

= 257 x 1000 

= 257000

257 x 432  + 257 x 354 + 257 x  214

=257.(432+354+214)

=257.1000=257000

=\(257\times\left(432+354+214\right)\)

=\(257\times1000\)

=\(257000\)

a) 425 x 3475 + 425 x 6525 = 425 x ( 3475 + 6525 ) = 425 x 10000 = 4250000

b) 3876 x 375 + 375 x 6124 = 375 x ( 3876 + 6124 ) = 375 x 10000 = 3750000

c) 275 x 432 + 257 x 354 + 257 x 124 = 275 x ( 432 + 354 + 124 ) = 275 x 910 = 250250

cau hoi 7

257x(38+41+21)

=257x100

25700

cau hoi 8

86x(121-119+9)

=86x11

=946

Câu 7:

257*(38+41+3+7)

=257*89

=22 873

Câu 8:

86*(121-119+9)

=86*11

=946

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a. = 267 + 864 - 263 - 860

= (267 - 263) + (864 - 860)

= 4 + 4

= 8

b. = [(257 + 37) x 35] : 60

= [294 x 35] : 60

= 10290 : 60

= 171,5

c. = [(139 - 39) x 257] : 100

= [100 x 257] : 100

= 25700 : 100

= 257

A. 234 x ( 1257 – 257 )   =  234 x 1257 - 234 x 257

B. 135 x 80 + 20 x 135    =   135 x ( 80 + 20 )