`a) (x+1/4-1/3) :(2 +1/6-1/4) = 7/46`
`=> x+1/4-1/3 = 7/46.(2+1/6-1/4)`
`=> x -1/12 = 7/46 . 23/12`
`=> x -1/12 = 7/24`
`=> x = 7/24 + 1/12`
`=> x = 3/8`
Vậy ` x=3/8`
`b) 13/15 - (13/41 +x) . 7/2 = 7/10`
`=> ( 13/41 + x ). 7/2 = 13/15 - 7/10`
`=> (13/41 + x ) .7/2 = 1/6`
`=> 13/41 + x = 1/6 : 7/2`
`=> 13/41 + x = 1/21`
`=> x = 1/21 - 13/41`
`=> x = -232/861`
Vậy ` x=-232/861`
