Question

Заранее ! решите систему {x/2=y/3 {x+y=4

Answer 1

Х/2-у/3=0
х+у=4

3х-2у=0   I
х+у=4     I 2
3х-2у=0
2х+2у=8
сложим
5х=8
х=1,6
у=4-х=2,4

Answer 2

$\left \{ {{ \frac{x}{2}= \frac{y}{3} } \atop {x+y=4}} \right. \\ \\ \left \{ {{3x=2y} \atop {x+y=4}} \right. \\ \\ \left \{ {{x=4-y} \atop {3(4-y)=2y}} \right. \\ \\ \left \{ {{x=4-y} \atop {12-3y=2y}} \right. \\ \\ \left \{ {{x=4-y} \atop {5y=12}} \right. \\ \\ \left \{ {{x=4-y} \atop {y= \frac{12}{5} }} \right. \\ \\ \left \{ {{y= \frac{12}{5} } \atop {x= \frac{8}{5} }} \right.$

ответ: $( \frac{8}{5} ; \frac{12}{5} )$