Question

Exercițiul 45. Va rog frumos!!​

Answer 1

$x=\frac{7y}{2}$

$\frac{3x+5y}{2x+y}=\frac{\frac{21y}{2}+\frac{10y}{2}}{7y +y}=\frac{\frac{31y}{2}}{8y}=\frac{31y}{16y}=\frac{31}{16}.$

Answer 2

Explicație pas cu pas:

$\bf\dfrac{x}{y} = \dfrac{7}{2} \implies 7y = 2x \implies y = \dfrac{2x}{7}$

$\bf \dfrac{3x+5y}{2x+y}=\dfrac{3x + 5 \cdot\dfrac{2x}{7}}{2x + \dfrac{2x}{7} } = \dfrac{3x + \dfrac{10x}{7}}{\dfrac{14x + 2x}{7} } =$

$\bf \dfrac{\dfrac{21x + 10x}{7}}{\dfrac{16x}{7} } = \dfrac{\dfrac{31x}{7}}{\dfrac{16x}{7} } = \dfrac{31x}{7} : \dfrac{16x}{7} =$

$\bf \dfrac{31 \not x}{ \not7} \cdot \dfrac{ \not7}{16 \not x} = \red{ \boxed{ \bf \: \dfrac{31}{16} \: }}$