Giải thích các bước giải:
Bài `1.`
`a)`
`(-3)/4+5/4`
`=(5-3)/4`
`=2/4`
`=1/2`
`b)`
`7/2+(-5)/3`
`=7/2-5/3`
`=21/6-10/6`
`=11/6`
`c)`
`4,5+(-1)/2`
`=45/10-1/2`
`=9/2-1/2`
`=8/2`
`=4`
`d)`
`-0,25+(-3/4)`
`=-25/100-3/4`
`=-1/4-3/4`
`=-4/4`
`=-1`
`e)`
`3/4+(-5/3)+5/3`
`=3/4+(5/3-5/3)`
`=3/4+0`
`=3/4`
`f)`
`(-4/3)+(-3/4)+7/12`
`=-4/3-3/4+7/12`
`=-16/12-9/12+7/12`
`=(-16-9+7)/12`
`=-18/12`
`=-3/2`