Question

determinati nr x si y pentru care multimile urmatoare sunt direct proportionale
A= 2 5 7 B= x 10 y
va rog urgent!!!!!!

Answer 1

A si B d.p. ⇔ (2;5;7) si (x;10x;y) d.p.

$\dfrac{2}{x} = \dfrac{5}{10} = \dfrac{7}{y} \iff \dfrac{2}{x} = \dfrac{1}{2} = \dfrac{7}{y}$

$\dfrac{2}{x} = \dfrac{1}{2} \Rightarrow x = 2 \cdot 2 \implies \bf x = 4$

$\dfrac{1}{2} = \dfrac{7}{y} \Rightarrow y = 2 \cdot 7 \implies \bf y = 14$