Question

am nevoie cat de repede puteti!! va rog!​

Answer 1

Răspuns:

a) 5/2

Explicație pas cu pas:

$\frac{x}{y} = 2 => x = 2y$

inlocuind in al doilea raport obtinem:

$\frac{(2y)^{2} + y^{2} }{(2y)y} =\frac{4y^{2} + y^{2} }{2y^{2} } =\frac{5y^{2} }{2y^{2} } = \frac{5}{2}$

Answer 2

$\it \dfrac{x}{y}=2 \Rightarrow x=2y\ \ \ \ \ \ (*)\\ \\ \\ \dfrac{x^2+y^2}{xy}\ \stackrel{(*)}{=}\ \dfrac{(2y)^2+y^2}{2y\cdot y}=\dfrac{4y^2+y^2}{2y^2}=\dfrac{5\not y^2}{2\not y^2}=\dfrac{5}{2}$