Question

Помогите с алгеброй!

Answer 1

$1); (x^2-8)^2=x^2-8\\x^2-8=t, ; t^2=t\\t^2-t=0\\t(t-1)=0\\t_1=0,; t_2=1\\a); x^2-8=0\\x^2=8\\x=pm sqrt8=pm 2sqrt2$

$b); x^2-8=1\\x^2=9\\x=pm 3\\Otvet:; -2sqrt2,; 2sqrt2,; -3,; 3.$

$2); left { {{frac{y+1}{x-2}=0} atop {x^2-y=5}} right. ; left { {{frac{x^2-5+1}{x-2}=0} atop {y=x^2-5}} right. \\frac{x^2-4}{x-2}=0; to ; left { {{x^2-4=0} atop {x-2ne 0}} right. ; left { {{(x-2)(x+2)=0} atop {xne 2}} right. ; left { {{x_1=-2,x_2=2} atop {xne 2}} right. to \\x=-2,; ; to ; ; y=(-2)^2-5=-1\\Otvet:; (-2,-1)$