rozwiązanie w załączniku
[latex]a)\ \egin{cases}4x+5y=-4 \6x+7y=-6 end{cases}\ \egin{cases}4x=-4-5y /:4\6x+7y=-6 end{cases}\ \egin{cases}x=-1-frac{5}{4}y \6*(-1-frac{5}{4}y )+7y=-6 end{cases}\ \egin{cases}x=-1-frac{5}{4}y \-6+frac{30}{4}y +7y=-6 end{cases}[/latex] [latex]egin{cases}x=-1-frac{5}{4}y \-6+7frac{1}{2}y +7y=-6 end{cases}\ \egin{cases}x=-1-frac{5}{4}y \14frac{1}{4}y=-6 +6end{cases}\ \egin{cases}x=-1-frac{5}{4}*0 \y=0 end{cases}\ \egin{cases}x=-1 \y=0 end{cases}[/latex] [latex]b)\ \egin{cases}-2x+5y=-10\7x-4y=8 end{cases}\ \egin{cases}-2x=-10-5y/:(-2)\7x-4y=8 end{cases}\ \egin{cases}x=5+frac{5}{2}y\7*(5+frac{5}{2}y)-4y=8 end{cases}\ \egin{cases}x=5+frac{5}{2}y\35+frac{35}{2}y-4y=8 end{cases}[/latex] [latex]egin{cases}x=5+frac{5}{2}y\17frac{1}{2}y-4y=8-35 end{cases}\ \egin{cases}x=2+frac{5}{2}y\13frac{1}{2}y=-27end{cases}\ \egin{cases}x=5+frac{5}{2}y\frac{27}{2}y=-27/*(frac{2}{27})end{cases} \ \egin{cases}x=5+frac{5}{2}*(-2)\y=-2end{cases}[/latex] [latex]egin{cases}x=5-5\y=-2end{cases} \ \ egin{cases}x=0\y=-2end{cases}[/latex] [latex]c)\ \egin{cases}9x+8y=1\5x-6y=11 end{cases}\ \egin{cases}9x=1-8y/:9\5x-6y=11 end{cases}\ \egin{cases}x=frac{1}{9}-frac{8}{9}y\5(frac{1}{9}-frac{8}{9}y)-6y=11 end{cases}\ \ egin{cases}x=frac{1}{9}-frac{8}{9}y\frac{5}{9}-frac{40}{9}y-6y=11 end{cases}[/latex] [latex]egin{cases}x=frac{1}{9}-frac{8}{9}y\-4frac{4}{9}y-6y=11-frac{5}{9} end{cases}\ \egin{cases}x=frac{1}{9}-frac{8}{9}y\-10frac{4}{9}y=10frac{4}{9} end{cases} \ \egin{cases}x=frac{1}{9}-frac{8}{9}y\-frac{94}{9}y=frac{94}{9}/*(-frac{9}{94}) end{cases}[/latex] [latex]egin{cases}x=frac{1}{9}-frac{8}{9}*(-1)\y=-1end{cases} \ \ egin{cases}x=frac{1}{9}+frac{8}{9}\y=-1end{cases} \ \ egin{cases}x=frac{9}{9}\y=-1end{cases} \ \ egin{cases}x=1\y=-1end{cases}[/latex]
