Zad 1.
[tex]\left \{ {{3x-2y=5} \atop {14x+y=3}} \right. \\\left \{ {{3x-2y=5} \atop {y=3-14x}} \right. \\\\3x-2(3-14x)=5\\3x-6+28x=5\\31x=5+6\\31x=11\\x=\frac{11}{31}\\14*\frac{11}{31}+y=3\\\frac{154}{31}+y=3\\y=3-\frac{154}{31}\\y=\frac{93}{31}-\frac{154}{31}\\y=-\frac{61}{31}\\y=-1\frac{30}{31}[/tex]
Zad. 2
[tex]\left \{ {{1-4x+2y=5} \atop {1x-3y=2}} \right. \\\left \{ {{-4x+2y=5-1} \atop {1x-3y=2}} \right. \\\left \{ {{-4x+2y=4} \atop {x-3y=2 /*4}} \right. \\+\left \{ {{-4x+2y=4} \atop {4x-12y=8}} \right. \\-10y=4+8\\-10y=12 /:(-10)\\y=-\frac{12}{10}\\y=-1\frac{2}{10}\\y=-1\frac{1}{5}\\x-3*(-\frac65)=2\\x+\frac{18}{5}=2\\x=2-\frac{18}{5}\\x=\frac{10}{5}-\frac{18}{5}\\x=-\frac{8}{5}\\x=-1\frac35[/tex]
Zad.3
[tex]\left \{ {{13(x-2)+4=5y-3} \atop {2(x-y)=3}} \right. \\\left \{ {{13x-26+4=5y-3} \atop {2x-2y=3}} \right. \\\left \{ {{13x-5y=-3+26-4} \atop {2x-2y=3}} \right. \\\left \{ {{13x-5y=19/*2} \atop {2x-2y=3 /*(-5)}} \right. \\\left \{ {{26x-10y=38} \atop {-10x+10y=-15}} \right. \\26x-10x=38-15\\16x=23 /:16\\x=\frac{23}{16} = 1\frac7{16}\\2*\frac{23}{16}-2y=3\\\frac{23}8-2y=3\\\frac{23}{8}-\frac{24}{8}=2y\\-\frac18=2y /*\frac12\\-\frac18*\frac12=y\\-\frac1{16}=y[/tex]
