Tính nhanh
a) (-77 – 23) – (567 – 77)
b) 7 – (-812 – 45) + (55 – 812)
c) (-13) – [2022 – (23 +2011)]
d) (72 – 56) – [(-123) + (-28+44)
Tính nhanh a) (-77 – 23) – (567 – 77) b) 7 – (-812 – 45) + (55 – 812) c) (-13) – [2022 – (23 +2011)] d) (72 – 56) – [(-123) + (-28+44)
By Mackenzie
Đáp án:
`a)=-590`
`b)=107`
`c)=-1`
`d)=123`
Giải thích các bước giải:
Ta có :
`a,(-77-23)-(567-77)`
`=-77-23-567+77`
`=(77-77)-(23+567)`
`=0-590`
`=-590`
`———-`
`b,7-(-812-45)+(55-812)`
`=7+812+45+55-812`
`=7+(812-812)+(55+45)`
`=7+0+100`
`=107`
`———–`
`c,(-13)-[2022-(23+2011)]`
`=-13-(2022-23-2011)`
`=-13-2022+23+2011`
`=(23-13)+(2011-2022)`
`=10+(-11)`
`=-1`
`———–`
`d,(72-56)-[(-123)+(-28+44)]`
`=72-56+123+28-44`
`=(72+28)-(56+44)+123`
`=100-100+123`
`=0+123`
`=123`
a)
(-77 – 23) – (567 – 77)
=-77-23-567+77
=(-77+77)+(-23-567)
=0+-590
=-590
b)
7 – (-812 – 45) + (55 – 812)
=7+812+45+55-812
=(812-812)+(45+55)+7
=0+100+7
=107
c)
(-13) – [2022 – (23 +2011)]
=-13-(2022-2024)
=-13-(-2)
=-13+2
=-11
d)
(72 – 56) – [(-123) + (-28+44)
=72-56+123-28+44
=(-56+44)-28+(72+123)
=-12-28+195
=-40+195
=155