Bài `5:`
a) `4/11x-1/3=2/5`
`=> 4/11x=2/5+1/3`
`=> 4/11x=6/15+1/15`
`=> 4/11x=7/15`
`=> x=7/15:4/11`
`=> x=77/60`
Vậy `x=77/60`
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b) `1/4+(-4)/3x=(-7)/5`
`=> (-4)/3x=(-7)/5-1/4`
`=> (-4)/3x=(-28)/20-5/20`
`=> (-4)/3x=(-33)/20`
`=> x=(-33)/20:(-4)/3`
`=> x=99/80`
Vậy `x=99/80`
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c) `(-6)/7-1/5x=-4`
`=> 1/5x=(-6)/7-(-4)`
`=> 1/5x=(-6)/7-(-28)/7`
`=> 1/5x=22/7`
`=> x=22/7:1/5`
`=> x=110/7`
Vậy `x=110/7`
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d) `1/2+2/3:x=(-5)/4`
`=> 2/3:x=(-5)/4-1/2`
`=> 2/3:x=(-7)/4`
`=> x=2/3:(-7)/4`
`=> x=(-8)/21`
Vậy `x=(-8)/21`
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e) `(-5)/2+x:7=(-1)/3`
`=> x:7=(-1)/3-(-5)/2`
`=> x:7=13/6`
`=> x=13/6.7`
`=> x=91/6`
Vậy `x=91/6`
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f) `(-3)/2-1/4:x=-1`
`=> 1/4:x=(-3)/2-(-1)`
`=> 1/4:x=(-1)/2`
`=> x=1/4:(-1)/2`
`=> x=(-1)/2`
Vậy `x=(-1)/2`
