Question

х+игрик=5
х2+игрик2=25

Answer 1

$left { {{x+y=5} atop {x^2+y^2=25}} right. ; left { {{(x+y)^2=5^2} atop {x^2+y^2=25}} right. ; left { {{x^2+y^2+2xy=25} atop {x^2+y^2=25}} right. ; left { {{25+2xy=25} atop {x^2+y^2=25}} right. ; left { {{2xy=0} atop {x^2+y^2=25}} right. \\ left { {{x=0; ili; y=0} atop {x^2+y^2=25}} right.; to \\a); ; left { {{x=0} atop {x^2+y^2=25}} right. ; ; ili; ; b); left { {{y=0} atop {x^2+y^2=25}} right. \\ left { {{x=0} atop {y^2=25}} right.$

$left { {{x=0} atop {y=pm 5}} right. \\b) left { {{y=0} atop {x^2=25}} right. ; left { {{y=0} atop {x=pm 5}} right. \\Otvet:; (0;-5),; (0;5),; (-5;0),; (5;0).$