若x+y=3,xy=1,则x2+y2=______.
9个回答
解 (x+y)^2=9
x^2+2xy+y^2=9
因为xy=1
所以x^2+2+y^2=9
x^2+y^2=7
相关问题
若1/X-1/Y=3,则2X+XY-2Y/X-2XY-Y=?
若[1/x+1y]=2,则[2x−xy+2y/3x+5xy+3y]=______
若2/x+2/y=1,则(2x-xy+2y)/(3x+5xy+3y)=?
若x2+y2=3,xy=1,则x-y=?
若xy/x+y=2,则3x-xy+3y/-x+3xy-y=
数学找规律填空(1)若x+y=2,则√xy≤1,(2)若x+y=3,则√xy≤2分之3(3)若x+y=6,则√xy≤3请
若[1/x]+[1/y]=2,则[2x+3xy+2y/x−xy+y]的值为______.
若x²+xy-2y²=0,则x²+3xy+y²/x²+y²
若1/x-1/y=2,则(3x+xy-3y)/(x-xy-y)的值为?
若1/x+1/y=2,则分式(2x+3xy+2y)/(x-xy+y)的值是?