Bài 12. Tính nhanh:
a) 25. ( -2). 5 . ( -4). 23 b) ( -4). 6. ( + 125). (-25). (-8)
c) 13.( -47) – 53. 13 d) 27. ( -67) + 33. ( – 27 )
d) – 49. 65 + 36. ( – 49) + 49 e) 125. (-61).(-2)3 . ( -1)2n với
g) 136. ( -47) + 36. 47 h) ( -48).72 + 36. ( -304)
HỘ EM VS E ĐG CẦN GẤP Ạ!
`a.25.(-2).5.(-4).23`
`=-50.5.(-4).23`
`=23,000`
`b.(-4).6.125.(-25).(-8)`
`=-3,000.(-25).(-8)`
`=-3,000.(-25).(-8)`
`=-600,000.`
`c.13.(-47)-53.13`
`=-611-689`
`=-1,300`
`d.27.(-67)+33.(-27)`
`=-1,009+(-891)`
`=-1,900.`
`d.-49.65+36.(-49)+49`
`=-3,185-1,765+49`
`=1,469`
`g.136.(-47)+36.47`
`=-6,392+1,692`
`=-4,7.`
`h.-48.72+36.(-304)`
`=-3,456-10,944`
`=14,4`
a) 25. ( -2). 5 . ( -4). 23
=[25.(-4)].[(-2).5].23
=(-100).(-10).23
=1000.23=23000
b) ( -4). 6. ( + 125). (-25). (-8)
= [(-4).(-25)].[(-8).125].6
=100.(-1000).6
=-100000.6=-600000
c) 13.( -47) – 53. 13
=13.(-47-53)
=13.(-100)=-1300
d) 27. ( -67) + 33. ( – 27 )
=27. ( -67) – 33. 27
=27.(-67-33)=27.(-100)=-2700
d) – 49. 65 + 36. ( – 49) + 49
= – 49. 65 + 36. ( – 49) -(-49)
=-49.(65+36-1)=-49.100=-4900
e)125. (-61).(-2)3 . ( -1)2n với?
=> thiếu dữ kiện, bạn xem lại.
g) 136. ( -47) + 36. 47
= 136. ( -47) – 36.(-47)
=-47.(136-36)
=-47.100=-4700
h) ( -48).72 + 36. ( -304)
= (-6).(-8).72 + (-6).(-6). 304
=(-6).[(-8).72-6.304]
=(-6).(-2400)=14400