$\dfrac{5x + 4}{6}$`-`$\dfrac{8x - 1}{3}$`=`$\dfrac{4x + 1 }{5 + 2}$
2 câu trả lời
`(5x+4)/6-(8x-1)/3=(4x+1)/(5+2)`
`<=>(5x+4)/6-(8x-1)/3=(4x+1)/7`
`<=>(7(5x+4))/42-(14(8x-1))/42=(6(4x+1))/42`
`=>7(5x+4)-14(8x-1)=6(4x+1)`
`<=>(35x+28)-(112x-14)=24x+6`
`<=>35x+28-112x+14=24x+6`
`<=>35x-112x-24x=6-28-14`
`<=> -101x=-36`
`<=>x=36/101`
Vậy `S={36/101}`
$\dfrac{5x+4}{6}-\dfrac{8x-1}{3}=\dfrac{4x+1}{5+2}$
$⇔ \dfrac{5x+4}{6}-\dfrac{8x-1}{3}=\dfrac{4x+1}{7}$
$⇔ \dfrac{7(5x+4)}{6.7}-\dfrac{14(8x-1)}{3.14}=\dfrac{6(4x+1)}{7.6}$
$⇔ \dfrac{35x+28}{42}-\dfrac{112x-14}{42}=\dfrac{24x+6}{42}$
$⇒ 35x+28-(112x-14)=24x+6$
$⇔ 35x+28-112x+14=24x+6$
$⇔ -77x+42=24x+6$
$⇔ -77x-24x=-42+6$
$⇔ -101x=-36$
$⇔ x=\dfrac{36}{101}$
Vậy phương trình có tập nghiệm `S={36/101}`
$#thanhmaii2008$
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