Question

(x - 3y) / (x + 3y) = 1 / 5
(4x + y) / (4x - y ) = ?
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Answer 1

Răspuns:

Explicație pas cu pas:

$\frac{x - 3y}{x + 3y} = \frac{1}{5}$

5(x - 3y) = x + 3y

5x - 15y = x + 3y

=> 4x = 18y

4x + y = 18y + y = 19y

4x - y = 18y - y = 17y

=>

$\frac{4x + y}{4x - y} = \frac{19y}{17y} = \bf \frac{19}{17}$

Answer 2

$\it \dfrac{x-3y}{x+3y}=\dfrac{1}{5} \Rightarrow 5x-15y=x+3y \Rightarrow 5x-x=3y+15y\Rightarrow 4x=18y\ \ \ \ \ (*)\\ \\ \\ \dfrac{4x+y}{4x-y}\ \stackrel{(*)}{=}\ \dfrac{18y+y}{18y-y}=\dfrac{\ 19y^{(y}}{17y}=\dfrac{19}{17}$