Question

Urgent
Va rog (De dorit pe foaie ) Metoda substitutiei

Answer 1

[tex] \left \{ {{3x+2y=4} \atop {x-2y=-2}} \right. \ \textless \ =\ \textgreater \ \left \{ {{3(-2+2y)+2y=4} \atop {x=-2+2y}} \right. \ \textless \ =\ \textgreater \ \left \{ {{-6+6y+2y=4} \atop {x=-2+2y}} \right. \ \textless \ =\ \textgreater \ \\ \left \{ {{8y=4+6} \atop {x=-2+2y}} \right. \ \textless \ =\ \textgreater \ \left \{ {{8y=10} \atop {x=-2+2y}} \right. \ \textless \ =\ \textgreater \ \left \{ {{y= \frac{10}{8}= \frac{5}{4} } \atop {x=-2+2* \frac{5}{4} }} \right. \ \textless \ =\ \textgreater \ \left \{ {{y= \frac{5}{4} } \atop {x=-2+ \frac{5}{2} }} \right.\ \textless \ =\ \textgreater \ \\ \left \{ {{y=\frac{5}{4}} \atop {x=\frac{-4+5}{2}}} \right. \ \textless \ =\ \textgreater \ [/tex]
$\left \{ {{y= \frac{5}{4} } \atop {x=\frac{1}{2}}} \right.$
S={1/2; 5/4}