Question

daca x supra y egal cu 3 supra 5 atunci aflati a)x+y supra y b)x supra xy c)2y supra 3y egal x d)2x+y supra 7y-2x​

Answer 1

Explicație pas cu pas:

$\dfrac{x}{y} = \dfrac{3}{5}$

a)

$\dfrac{x + y}{y} = \dfrac{3 + 5}{5} = \dfrac{8}{5}$

b)

$\dfrac{x}{xy} = \dfrac{1}{y}$

$\dfrac{x}{y} = \dfrac{3}{5} \iff \dfrac{1}{y} = \dfrac{3}{5x} \implies \dfrac{x}{xy} = \dfrac{3}{5x}$

c)

$\dfrac{2y}{3y} = x \implies x = \dfrac{2}{3}$

$\dfrac{x}{y} = \dfrac{3}{5} \iff y = \dfrac{5x}{3} = \dfrac{5}{3} \cdot \dfrac{2}{3} \\ \implies y = \dfrac{10}{9}$

d)

$\dfrac{2x + y}{7y - 2x} = \dfrac{2 \cdot 3 + 5}{7 \cdot 5 - 2 \cdot 3} = \dfrac{6 + 5}{35 - 6} = \dfrac{11}{29}$