Question

Sa se afle numerele x si y stiind ca sunt direct proportionale cu 3 si 5 si au suma patratelor
306

Answer 1

Avem3x=5y=>x=5y/3
xpatrat+ypatrat=306
(5y/3)patrat+ypatrat=306
25ypatrat/9+ypatrat=306
Se,aduce,la,numitor,comun,adica,9,si,avem
25ypatrat+9ypatrat=2754
34ypatrat=2754
ypatrat=81=>y=9
xpatrat=306-81
xpatrat=225=>x=15

Answer 2

[tex] \frac{x}{3} = \frac{y}{5} \;\Leftrightarrow\; \frac{x^2}{3^2} = \frac{y^2}{5^2} = \frac{306}{9+25}=9\;\\ \\ x=\sqrt{9\cdot9}=9\;si\;y=\sqrt{25\cdot9}=15 [/tex]