`1a,-3/8-7/25*15/16+3/8:10/7`
`=-3/8-21/80+21/80`
`=-3/8`
`b,(-4/5*5/-8):-25/12`
`=1/2:-25/12`
`=-6/25`
`c,5/8+2 1/4 * 1 2/3 -1/4*5/6`
`=5/8+15/4-5/24`
`=25/6`
`d,2/9+4/15:2/-25+1/3`
`=2/9-10/3+1/3`
`=-25/9`
`2a,-3/5 : x=4/3`
`<=>x=-9/20`
`b,1/4x+3/8=-1/2`
`<=>1/4x=-7/8`
`<=>x=-7/2`
`c,-1/10+2/5x=7/20`
`<=>2/5x=9/20`
`<=>x=9/8`
`d,3/4+1/4:x=2/5`
`<=>1/4:x=-7/20`
`<=>x=-5/7`
`e,(5/7-x)*5/7-25/49=0`
`<=>(5/7-x)*5/7=25/49`
`<=>5/7-x=5/7`
`<=>x=0`
`f,(4/5+x):1/5-4/7=5 13/14`
`<=>(4/5+x):1/5 =13/2`
`<=>4/5+x=13/10`
`<=>x=1/2`
Vậy .....
