Trudno rozczytac co tu jest napisane ale sprobuje.
Zad. 1
[tex]\left \{ {{3x+6y=4/*5} \atop {5x+4y=-2/*(-3)}} \right. \\\left \{ {{15x+30y=20} \atop {-15x-12y=6}} \right. \\30y-12y=20+6\\18y=26/:18\\y=\frac{26}{18}=\frac{13}9=1\frac49\\5x+4*\frac{13}9=-2\\5x+\frac{52}9=-2 /-\frac{52}9\\5x=-\frac{18}9-\frac{52}9\\5x=-\frac{70}9 /*\frac15\\x=-\frac{14}9[/tex]
Zad. 2
[tex]\left \{ {{x-2y=6} \atop {x+1=2(3-y)}} \right. \\\left \{ {{x-2y=6} \atop {x+1=6-2y}} \right. \\\left \{ {{x-2y=6} \atop {x+2y=6-1}} \right. \\\left \{ {{x-2y=6} \atop {x+2y=5}} \right. \\2x=6+5\\2x=11/:2\\x=\frac{11}2\\\\x+2y=5\\\frac{11}2+2y=5 /-\frac{11}2\\2y=\frac{10}2-\frac{11}2\\2y=-\frac12 /*\frac12\\y=-\frac14[/tex]
[tex]\left \{ {{y-\frac{5-2x}2=-3 /*2} \atop {\frac{x-2y}3=\frac13(x-y)-\frac32 /*3}} \right. \\\left \{ {{2y-5-2x=-6} \atop {x-2y=x-y-\frac92}} \right. \\\left \{ {{2y-2x=-6+5} \atop {x-x-2y+y=-\frac92}} \right. \\\left \{ {{2y-2x=-1} \atop {-y=-\frac92}} \right. \\\left \{ {{2*\frac92-2x=-1} \atop {y=\frac92}} \right. \\\left \{ {{9-2x=-1 /-9} \atop {y=\frac92}} \right. \\\left \{ {{-2x=-10 /:(-2)} \atop {y=\frac92}} \right. \\\left \{ {{x=5} \atop {y=\frac92}} \right.[/tex]
Szczegółowe wyjaśnienie:
