Đáp án+Giải thích các bước giải:
`d) x+5/2x-3/2= 2 1/4`
`<=> x(1+5/2)-3/2= 9/4`
`<=> x(2/2+5/2)=9/4+3/2`
`<=> 7/2x = 9/4 + 6/4`
`<=> 7/2x = (15)/4`
`<=> x = (15)/4 : 7/2`
`<=> x = (15)/4 . 2/7`
`<=> x = (15)/(14)`
Vậy `x = (15)/(14)`
`e) (5x-1)(2x-1/3)=0`
`<=>`\(\left[ \begin{array}{l}5x-1=0\\2x-\dfrac{1}{3}=0\end{array} \right.\)
`<=>`\(\left[ \begin{array}{l}5x=1\\2x=\dfrac{1}{3}\end{array} \right.\)
`<=>`\(\left[ \begin{array}{l}x=\dfrac{1}{5}\\x=\frac{1}{6}\end{array} \right.\)
Vậy `x∈{1/5; 1/6}`
`f) 3/7+1/7:x=3/(14)`
`<=> 1/7 :x = 3/(14) - 3/7`
`<=> 1/7 :x = 3/(14) - 6/(14)`
`<=> 1/7 :x =-3/(14)`
`<=> x = 1/7 : (-3)/(14)`
`<=> x = 1/7 . (-14)/3`
`<=> x = -2/3`
Vậy `x=-2/3`
