Ex.1)[tex]a)(x+y-2)^{2} +(2x-y+1) ^{2}=0,x,y~apartin~R \\ b)|2x-y+1|+|x+2y+3|=0,x,y~apartin~R \\ c) \sqrt{x+2y} +|3x-y-1|=0,x,y~apartin~R \\ d) x^{2} +2xy+2y ^{2} -6y+9=0,x,y~apartin~R[/tex]
Ex 2)
[tex]Rezolva~ sistemele: \\ \\ a) \left \{ {{x \sqrt{2}+y \sqrt{3}=2 \sqrt{6}}\atop {x \sqrt{3}-y \sqrt{2}=0}} \right. \\ b) \left \{ {{ \frac{x+1}{y-2}=1 } \atop {2x+3y=2}} \right. \\ c) \left \{ {{ \frac{2x+y-1}{x+3}=1 } \atop {3x-y=-2}} \right. \\ d) \left \{ {{ \frac{y-1}{x+1}= \frac{y+2}{x-1} } \atop {3+2* \frac{y+1}{x-1} = \frac{2-y}{x-1} }} \right. [/tex]
Macar unul dintre exercitii(complet facut)