Tính hợp lí ( nếu được )
47 . ( 23 + 50 ) - 23 . ( 47 + 50 )
85 . ( 35 - 47 ) - 35 . ( 85 - 27 )
tính hợp lí
a)29.(85-47)+85.(47-29)
b)47.(23+50)-23.(47+50)
a) 29.(85-47)+85.(47-29)= 29.85-29.47+85.47-85.29
=(29.85-85.29) -29.47+85.47
=0-29.47+85.47
= -29.47+85.47
= (-29+85).47
=56.47
= 2632
b)47.(23+50)-23.(47+50)= 47.23+47.50-23.47+23.50
=(47.23-23.47)+47.50+23.50
=0+47.50+23.50
=47.50+23.50
=(47+23).50
=70.50
=3500
tích ^.^ ~
a) 29.(85-47)+85(47-29)
=29.38+85.18
=1102+1520
=2622
b)47.(23+50)-23.(47+50)
=47.73-23.97
=3431-2231
=1200
k mình nha...^_^...kb nữa... thanks
tính hợp lí
a,85.(35-27)-35.(85-27)
b,47.(45-15)-47.(45+15)
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
3.Tính hợp lí
a, 21.35-3.25.7
b, 77-11.(30+7)
c, 85.(35-27)-35.(85-27)
d, 47.(45-15)-47.(45+15)
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
Tính hợp lí:
a. -29.(85-47)-85.(47-29)
b. 37.(29-23)-29.(37-23)
c. 5.2004-1002.(-10)+40.501
tính một cách hợp lý :
21 . 35 - 3 . 25 . 7
77 - 11 ( 30 + 7 )
85 ( 35 - 27 ) - 35 ( 85 - 27 )
47 ( 45 - 15 ) - 47 ( 45 + 15 )
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
Tính:
a) 85.(35 - 27) - 35.(85 -27)
b) 47. (45 - 15) - 47.(45+15)
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
tính nhanh:
a) 85.(35-27) - 35.(85-27) =
b) 47.(45-15) - 47.(45+15) =
a)85.(35-27)-35.(85-27)
=85.35-27-35.85-27
=(85-85).(35-35).(27-27)
=0.0.0
=0
b)47.(45-15)-47.(45+15)
=47.45-15-47.45+15
=(47-47).(45-45).(15+15)
=0.0.30
=0
a) 85 . ( 35 - 27 ) - 35 . ( 85 - 27 )
= 85 . 35 - 85 . 27 - 35 . 85 + 35 . 27
= ( 85 . 35 - 35 . 85 ) - 27 . ( 85 - 35 )
= 0 - 27 . 50
= 0 - 1350
= -1350
b) 47 . ( 45 - 15 ) - 47 . ( 45 + 15 )
= 47 . ( 45 - 15 - 45 - 15 )
= 47 . (-30)
= -1410
Học tốt !!!
=))
tính hợp lý
c1, -56+8(11+7)
c2, 47(23+50)-23(47+50)
c3, 85(47-29)+29(85-47)
c4, (-16)(-25)(-12)
c5, -19(16-25)+19(25-4)
c6, 11(16+24)+24(11-16)
c7, 29(85-47)-23(15-29)
c8, 15(23-29)+23(15-29)
c9, 13(55-29)-55(13-29)
c10, 37(27+25)+72(-25)
c11, (-216).68+32(-312)
c12, 44(-50)-50.56
c13, -69(-4).2-3(-7)(-2)
c14, 25.11.(-15)-50.15(-5)
c15, 47.69+31.(-47)
4. Tính. a) (-35) + 23 – (-35) – 47 b) 24 – (-136) – (-70) + 15 + (-115) c) 37 – (-43) + (-85) – (-30) + 15.
`@` `\text {Ans}`
`\downarrow`
`4.`
`a)`
\((-35) + 23 – (-35) – 47\)
`= (-35) + 23 + 35 - 47`
`= (-35 + 35) + (23 - 47)`
`= -24`
`b)`
\( 24 – (-136) – (-70) + 15 + (-115)\)
`= 24 + 136 + 70 + 15 - 115`
`= (24+136) + 70 + (-115 + 15)`
`= 160 + 70 - 100`
`= 160 - 30`
`= 130`
`c)`
\(37 – (-43) + (-85) – (-30) + 15\)
`= 37 + 43 - 85 + 30 + 15`
`= (37+43) + 30 - (85 - 15)`
`= 80 + 30 - 70`
`= 110 - 70`
`= 40`