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hok tốt

85.[35-27]-35.[85-27]

=85.35-85.27-35.85+35.27

=85.27+35.27

=27(85+35)

=27.120

=3240

a,
       85.(35-27)-35.(85-27)
     =85.35-85.27-35.85-35.27
     =85.35-35.85-85.27.35.27
     =85.27-35.27
     =(85-35).27
     =100.27/2
     =2700/2
     =1350

 (42-69+17)-(42+17)

=42-69+17+(-42)-17

=[42+(-42)]+[17+(-17)]-69

=0+0-69

=0-69

=-69

Bài làm

a) ( 42 - 69 + 17 ) - ( 42 - 17 )

= 42 - 69 + 17 - 42 + 17

= 42 - 69 - 42 + 34

= 34 - 69

= -35

b) 85 x ( 35 - 27 ) - 35 x ( 85 - 27 )

= 85 x 35 - 85 x 27 - 35 x 85 + 35 x 27

= ( 85 x 35 - 35 x 85 ) - ( 85 x 27 + 35 x 27 )

= 0 - [ 27 x ( 85 + 35 ) ]

= 0 - [ 27 x 120 ]

= 0 - 3240

= -3240

# Học tốt #

21.35-3.25.7

= 21.35-21.25

= 21.(35-25)

= 21. 10

=210

77 - 11.( 30+7)

= 11.7 -11.30 -11.7

= 11.7-11.7 -11.30

= -11.30

= -330

21.35-3.25.7=210

77-11(30+7)=-330

85(35-27)-35(85-27)=-1350

47(45-15)-47(45+15)=-2820

Từ biểu thức, ta suy ra:

85.35-85.27-35.85+35.27

=27(35-85)

=27.-50

=-1350

\(85.\left(35-27\right)-35.\left(85-27\right)\)

\(=85.8-35.58\)

\(=680-2030\)

\(=-1350\)

Chúc bạn học tốt~~~

a, 21.35-3.25.7=21.35-21.25=21.(35-25)=21.10=210

b, 77-11.(30+7)=77-330-77=-330

c, 85.(35-27)-35.(85-27)=85.35-85.27-35.85+35.27=0

d, 47.(45-15)-47.(45+15)=47.45-47.15-47.45-47.15=-2(47.15)=1410

a, 21.35-3.25.7=21.35-21.25=21.10=210

b,77-11.(30+7)=77-11.30-11.7=-11.30=-330

c,85.(35-27)-35.(85-27)=85.35-85.27-85.35+35.27=27.(-50)=-1350

d, 47.(45-15)-47.(45+15)=47.45-47.15-47.45-47.15=-47.30=-1410

85.(35-27)-35(85-27)=85.35-85.27-35.85+35.27

=(85.35-35.85)+(85.27-35.27)=0+27.(85-35)=27.40=1080

85.(35-27)-35(85-27)

=85.35-85.27-35.85+35.27

=(85.35-35.85)+(85.27-35.27)

=0+27.(85-35)=27.40=1080

tick nhé

\(47\left(23+50\right)-23\left(47+50\right)=47.23+47.50-23.47-23.50=50\left(47-23\right)=1200\)

\(85\left(35-47\right)-35\left(85-27\right)=85.35-85.47-85.35+35.27=35.27-85.47=-3050\)

a, 85.(35-27)-35.(85-27)

=85.35-85.27-35.85+35.27

=85.27+35.27

=27.(85+35)

=27.120=3240

b, 47.(45-15)-47.(45+15)

=47.30-47.60

=47.(30-60)

=-1410

thanks!