a) x : (1/7 - 3/14) = -4 3/8
<=> x : (-1/14) = 4 -3/8
<=> x = 4 -3/8 x (-1/14)
<=> x = -35/8 x (-1/14)
<=> x = 5/16
b) 1/3x + 2/5x - 2/5 = 0
<=> 1/3x + 2/5x = 0 + 2/5
<=> x(1/3 + 2/5) = 2/5
<=> 11/15x = 2/5
<=> x = 2/5 : 11/15
<=> 6/11
c) x^3 - 1/25x = 0
<=> x(x^2 - 1/25) = 0
=> x = 0 hoặc x^2 - 1/25 = 0
* x^2 - 1/25 = 0
<=> x^2 = 0 - 1/25
<=> x^2 = -1/25
=> x không có nghĩa
=> vậy x = 0
#Lynkk
a: \(\Leftrightarrow x:\dfrac{-1}{14}=\dfrac{-35}{8}\)
hay \(x=\dfrac{35}{8}\cdot\dfrac{1}{14}=\dfrac{5}{16}\)
b: =>11/15x-2/5=0
=>11/15x=2/5
hay x=22/75