Question

Выберите систему уравнений, решением который является пара чисел (-1.2)

Answer 1

1)$left { {{frac{1}{x}-frac{1}{y} =3 } atop {x^{2}+2y^{2} =5 }} right. => left { {{-frac{1}{1}-frac{1}{2}=3 } atop {(-1)^{2}+2*2^{2}=5 }} right. =>left { {{-1,5=3} atop {9=5}} right. => (-)$

2)$left { {{x^{2}+3y^{2}=13 } atop {x+3y=5}} right. =>left { {{(-1)^{2}+3*2^{2}=13 } atop {-1+3*2=5}} right. =>left { {{13=13} atop {5=5}} right. =>(+)$

3)$left { {{3x+2y=1} atop {x^{2}-y^{2}=-4 }} right. =>left { {{3*(-1)+2*2=1} atop {(-1)^{2} -2^{2}=-4 }} right. =>left { {{1=1} atop {-3=-4}} right. =>(-)$

4)$left { {{x-y=1} atop {(x-1)(y+2)=2}} right. =>left { {{-1-2=1} atop {(-1-1)(2+2)=2}} right. =>left { {{-3=1} atop {-8=2}} right. =>(-)$

Ответ:2

Answer 2

СПАСИБО БОЛЬШОЕ!!!!!!!!!!!!!!1