Đáp án:
`b)` Sửa `(x-5)/10+(x-7)/8+(x-1)/14=13->(x-5)/10+(x-7)/8+(x-1)/14=3`.
Giải thích các bước giải:
`a)(x+6)/8+(x+8)/6+(x+1)/13+3=0`
`<=>[(x+6)/8+1]+[(x+8)/6+1]+[(x+1)/13+1]=0`
`<=>(x+14)/8+(x+14)/6+(x+14)/13=0`
`<=>(x+14)(1/8+1/6+1/13)=0`
`<=>x+14=0` do `1/8+1/6+1/13>0`
`<=>x=-14`
Vậy `x=-14.`
`b)(x-5)/10+(x-7)/8+(x-1)/14=3`
`<=>[(x-5)/10-1]+[(x-7)/8-1]+[(x-1)/14-1]=0`
`<=>(x-15)/10+(x-15)/8+(x-15)/14=0`
`<=>(x-15)(1/10+1/8+1/14)=0`
`<=>x-15=0` do `1/10+1/8+1/4>0`
`<=>x=15`
Vậy `x=15.`
