=2*2*51*7+2*2*7*43+2*2*7*6

=2*2*7*(51+43+6)

=28*100

=2800

Lưu ý: * là dấu nhân

Ok Chúc bạn học tốt

2800

4.51.7+2.86.7+12.2.7

=1428+1204+168

=2800

4 . 51 . 7 + 2 . 86 . 7 + 2 . 7 . 12

= ( 4 . 51 ) . 7 + ( 2 . 86 ) . 7 + ( 2 . 12 ) . 7

= 204 . 7 + 172 . 7 + 24 . 7

= 7 . ( 204 + 172 + 24 )

= 7 . 400

= 2 800

2800

4.51.7+2.86.7+12.2.7

 = 2.7.2.51+ 2.2.7.43+ 2.2.7.6 

=2.2.7 .( 51+43+6) 

= 28 . 100 

= 2800

\(4.51.7+2.86.7+12.2.7=\left(4.51.7\right)+\left(2.86.7\right)+\left(12.2.7\right)=1428+1204+168=2632+168=2800\)

    4.51.7 + 2.86.7 + 12.2.7

= 2.2.51.7 + 2.7.86 + 2.7.12

= 2.7.102 + 2.7.86 + 2.7.12

= 2.7 ( 102 + 86 + 12)

= 14 . 200

= 2800

=1428+1204+28=2660

204*7+172*7+4*7=7*(204+172+4)=7*380=2660
 

=2x7(2x51+86+12)

=14.(102+86+12)

=14.200

=2800

=2800 đó bn

= 7 * (20 + 172 + 4 ) = 7* 196= 1372 nha bạn 

4.51.7+2.86.7+2.2.7

=(4.7).51+(2.7.2).43+(2.2.7)

=28.51+28.43+28.1

=28.(51+43+1)

=28.95=2660

a) 

4 . 5 . 7 + 2 . 86 . 7 + 12 . 2 . 7

= 20 . 7 + 172 . 7 + 24 . 7

= 7 . (20 + 172 + 24)

= 7 . 216

= 1512

b)

237 + 301 + 183 + 219

= (237 + 183) + (301 + 219)

= 420 + 520

= 940

k mk nha DuongthiHongDuyen !

41.36+59.90+41.81+59.30=11877

4.51.7+2.86.7+12.2.7=2800

x=1964

x=1500