Mng ơi giúp em với ạ Question Mng ơi giúp em với ạ in progress 0 Môn Toán Ben Gia 5 years 2021-05-23T13:54:32+00:00 2021-05-23T13:54:32+00:00 2 Answers 27 views 0
Answers ( )
Cho mik xin ctlhn ak☺️☺️????????♀️

Đáp án:
a) `-3/5`
b) `-16/21`
c) `3/2`
d) `-2019/2020`
Giải thích các bước giải:
a)
`7/9 . (-3)/5 + (-3)/5 . 2/9 = (7/9+2/9) . (-3)/5`
`=(-3)/5 . 1=-3/5`
b)
`4/7+5/6 : 5-0,375.(-2)^2=4/7+1/6-3/2`
`=(24+7-63)/42=-32/42=-16/21`
c)
`1 4/23+(5/21-4/23)+16/21-1/2`
`= 1 + 4/23+5/21-4/23+16/21-1/2`
`= (1-1/2)+(4/23-4/23)+(5/21+16/21)`
`=1/2+0+1=3/2`
d)
`123/345 . (1/4+1/12-1/3)-2019/2020`
`=123/345 . (3+1-4)/12-2019/2020`
`=0-2019/2020=-2019/2020`