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

a)21.35-3.25.7

=21.35-(3.7).25

=21.35-21.25

=21.(35-25)

=21.10=210

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

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

=0+27.(35-85)

=27.(-40)

=-1080

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

= 85.35-85.27-35.85-35.27

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

=0+27.(35-85)

=27.(-40)

= 1080

  (-27).35-35.38+35.(-45)+35.10

=(-27).35+35.(-38)+35.(-45)+35.10

=35.[-27+(-38)+(-45)+10]

=35.(-100)

=-3500

( -27)  . 35 - 35 . 38 + 35. ( - 45 ) + 35 .10

= 35 . [ ( - 27 ) - 38 - 45 + 10 ]

= 35 . [ - 65 - 45 + 10 ]

= 35 . [ - 110 + 10 ]

= 35 . ( - 100)

= - 3500

@@ Học tốt

=35.(-27-38-45+10)

=35.(-100)

=-3500

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

=85.35-85.27-35.85-35.27

=27.(-85-35)

=-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

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~~~

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

\(=85.8-35.58\)

\(=680-2030\)

\(=-1350\)

 (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 #

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

=42-69+17-42+17

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

=-69+34

=-35

a) \(-\left(76-35+15\right)+\left[18-27+\left(-17\right)\right]\)

\(=-76+35+15+18-27-17\)

\(=-52\)

b) \(167+\left[127-235-\left(-16\right)\right]+\left(-67\right)\)

\(=167+127-235+16-67\)

\(=8\)

c) \(\left(-19\right)+165-\left[27+\left(-21\right)-\left(+72\right)\right]\)

\(=\left(-19\right)+165-27+21+72\)

\(=212\)

d) \(89.\left(-2\right)+\left[20+\left(-2\right).\left(-5\right)-85\right]\)

\(=\left(-178\right)+\left(20+10-85\right)\)

\(=\left(-178\right)+20+10-85\)

\(=-233\)

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

a, 21 . 35 - 3 . 25 . 7

= (21 . 35) - (3 . 25 . 7)

= 735 - 525

= 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