1)2x+3y-(5x-y)=x+2y-(2x+3y)2x+3y-5x+y=x+2y-2x-3y2x-5x-x+2x=2y-3y-3y-y-2x=-5yx=2,5y2)(xy+1)/(y+1)²=(x-1)²/(xy+1)(2,5y²+1)/((y+1)²=(2,5y-1)²/(2,5y²+1)6,25y^4 +5y²+1=6,25y^4-5y³+y²+12,5y³-10y²+2y+6,25y²-5y+17,5y³-7,75y²-3y=0y(7,5y²-7,75y-3)=0y=0 -не удов усл7,5y²-7,75y-3=0D=60,0625+90=150,0625 √D=12,25y1=(7,75-12,25)/15=-0,3⇒x1=2,5*(-0,3)=-0,75y2=(7,75+12,25)/15=4/3⇒x2=5/2*4/3=10/3(-0,75;-0,3) U (10/3;4/3)