Đáp án:
Giải thích các bước giải:
`a) 3/7 - 1/21x = 1/3`
`1/21x = 3/7 - 1/3 `
`1/21x = 2/21
`x = 2/21 : 1/21 `
`x = 2`
`b) 3/2 - (x - 5/3) = 3/4`
`x - 5/3 = 3/2 - 3/4`
`x - 5/3 = 3/4`
`x = 3/4 + 5/3`
`x = 29/12`
`c) -4/7 x + 7/5 = 1/8 : (-1 2/3)`
` -4/7 x + 7/5 = 1/8 : (-5/3)`
` -4/7 x + 7/5 = -1/8`
`-4/7 x = -1/8 - 7/5`
` -4/7 x = -61/40`
` x = -61/40 : -4/7`
` x = 91/32`
`e)(x - 2/7)(x + 5/4) = 0`
`⇒` \(\left[ \begin{array}{l}x - \dfrac{2}{7} = 0 ⇒ x = \dfrac{2}{7}\\x + \dfrac{5}{4} ⇒ x = (-\dfrac{5}{3}) \end{array} \right.\)
`g) (1/2 + 1,5).x = 1/5`
`⇒ (1/2 + 3/2).x = 1/5`
`⇒ 2x = 1/5`
`⇒ x = 1/5 : 2`
`⇒ x = 1/10`
$#Zero#$
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