Question

Calcule o valor de x e y na proporção x/y = 3/4 , sabendo que x + y = 35 .

Answer 1

$\large\boxed{\begin{array}{l}\begin{cases}\rm\dfrac{x}{y}=\dfrac{3}{4}\\\rm x+y=35\end{cases}\\\\\rm\dfrac{x}{y}=\dfrac{3}{4}\\\\\rm\dfrac{x}{3}=\dfrac{y}{4}=k\\\\\rm x=3k~~y=4k\\\rm x+y=35\\\rm 3k+4k=35\\\rm 7k=35\\\rm k=\dfrac{35}{7}\\\\\rm k=5\\\rm x=3k=3\cdot5=15\\\rm y=4k=4\cdot5=20\end{array}}$