1.已知x+y=7 , xy=20 ,则下x^2+y^2=
2.若x^2+2x-1=0 , 那么5x^2+10x-3=
3.若多项式x^2-5x+4=(x+a)(x+b),则a= ,b=
4.(x-1/x)^2 +______=(x+1/x)^2
5.(2/3)^2005 * (-3/2)^2006的计算结果是
1.已知x+y=7 , xy=20 ,则下x^2+y^2=
2.若x^2+2x-1=0 , 那么5x^2+10x-3=
3.若多项式x^2-5x+4=(x+a)(x+b),则a= ,b=
4.(x-1/x)^2 +______=(x+1/x)^2
5.(2/3)^2005 * (-3/2)^2006的计算结果是
9
2
-1,-4
4
3/2
1、X^2+Y^2=(X+Y)^2-2XY=9
2、X^2=-(2X-1) 5X^2+10X-3=-10X+5+10X-3=2
3、a=-1 b=-4
4、4
9
2
-1,-4
4
3/2