Ребят помогите!!! кто решит тому сотку скину на киви!!!

№1 a)[latex] \left \{ {{2x-3y=-8} \atop {x^2-2xy-y^2=1}} \right. [/latex] Если [latex](-1;2)[/latex], то [latex] \left \{ {{2*(-1)-3*2=-8} \atop {(-1)^2-2*(-1)*2}-2^2=1} \right. \left \{ {{-2-6=-8} \atop {1+4-4=1}} \right. \left \{ {{-8=-8} \atop {1=1}} \right. [/latex] б)[latex] \left \{ {{x-y=-3} \atop {1-xy=-2}} \right. [/latex] Если [latex](-1;2)[/latex], то  [latex] \left \{ {{-1-2=-3} \atop {1-(-1)*2=-2}} \right. \left \{ {{-3=-3} \atop {3=-2}} \right. [/latex] Ответ: не является №2 [latex] \left \{ {{x+5y=7} \atop {2x+3y=7}} \right. \left \{ {{x=7-5y} \atop {2(7-5y)+3y=7}} \right. \left \{ {{x=7-5y} \atop {14-10y+3y=7}} \right. \left \{ {{x=7-5y} \atop {-7y=-7}} \right. \left \{ {{x=7-5} \atop {y=1}} \right. \left \{ {{x=2} \atop {y=1}} \right. [/latex] Ответ: [latex](2;1)[/latex] №3 [latex] \left \{ {{3x-y=7 \atop {5x+2y=8}} \right. \left \{ {{6x-2y=14} \atop {5x+2y=8}} \right. |+ \left \{ {{3x-y=7} \atop {11x=22}} \right. \left \{ {{6-y=7} \atop {x=2}} \right. \left \{ {{y=-1} \atop {x=2}} \right. [/latex] Ответ: [latex](2;-1)[/latex] №4 [latex] \left \{ {{2x+3y=12} \atop {x-y=1}} \right. \left \{ {{3y=12-2x} \atop {y=x-1}} \right. \left \{ {{y=4- \frac{2}{3}x } \atop {y=x-1}} \right. [/latex] №5 [latex]6x-5y[/latex] [latex] \left \{ {{x+3y=6} \atop {2x-y=5}} \right. \left \{ {{-2x-6y=-12} \atop {2x-y=5}} \right. \left \{ {{x+3y=6} \atop {-7y=-7}} \right. \left \{ {{x+3=6} \atop {y=1}} \right. \left \{ {{x=3} \atop {y=1}} \right. [/latex] [latex]6*3-5*1=18-5=13[/latex] №6 [latex] \left \{ {{ax+3y=9b} \atop {5x+ay=b}} \right. [/latex] [latex](1;-1)[/latex] [latex] \left \{ {{a-3=9b} \atop {5+a=b}} \right. \left \{ {{a-9b=3} \atop {a-b=-5}} \right. \left \{ {{a-9b=3} \atop {-a+b=5}} \right.|+ \left \{ {{-8b=8} \atop {a-b=-5}} \right. \left \{ {{b=-1} \atop {a+1=-5}} \right. \left \{ {{b=-1} \atop {a=-6}} \right. [/latex]