Question

решите срочно надо ???

Answer 1

1 Задание
а) 
$left { {{2x+y=1} atop {5x+2y=0}} right. \ left { {{y=1-2x} atop {5x+2*(1-2x)=0}} right. \ left { {{y=1-2x} atop {5x+2-4x=2}} right. \ left { {{y=1-2x} atop {x=0}} right. \ left { {{y=1} atop {x=0}} right.$
Ответ: y=1, x=0
б)
$left { {{x-y=4} atop { x^{2}- y^{2} =40}} right. \ left { {{x=y+4} atop { (y+4)^{2}- y^{2} }=40} right. \ left { {{x=y+4} atop { y^{2}+16+8y-y^2 }=40 right. \ left { {{x=y+4} atop {8y=24}} right. \ left { {{x=y+4} atop {y=3}} right. \ left { {{x=7} atop {y=3}} right.$
Ответ: x=7,y=3

2 Задание
$left { {{y=4-x^2} atop {x-y+2=0}} right. \ left { {{y=4-x^2} atop {x-4+x^2+2=0}} right. \ left { {{y=4-x^2} atop {x^2+x-2=0}} right. \ left { {{y=4-x^2} atop { x_{1} =1; x_{2} =-2}} right. \ left { {{ y_{1}=3; y_{2}=0 } atop {x_{1} =1; x_{2} =-2}} right.$