Question

se x+y=10 e x-y=7 de o valor número de x/2+y/3

Answer 1

$\begin{cases}x+y=10\\ x-y=7\end{cases}(+)~2x=17 \Rightarrow x= \dfrac{17}{2} ;~~ \\ \\ x+y=10 \\ \dfrac{17}{2}+y=10 \Rightarrow y=10- \dfrac{17}{2} \Rightarrow y= \dfrac{3}{2} \\ \\ \dfrac{x}{2} + \dfrac{y}{3} = \dfrac{ \dfrac{17}{2} }{2} + \dfrac{ \dfrac{3}{2} }{3}= \dfrac{17}{4} +\dfrac{3}{6}= \dfrac{51+6}{12} = \dfrac{57}{12} \\ \\ \\ .$