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已知x的2次方加y的2次方加xy减3y加3等于0,求x的y...

x2+y2+xy-3y+3=0 (x2+xy+1/4*y2)+(3/4*y2-3y+3)=0 (x+y)^2+3(1/2y-1)^2=0 x+y=0 1/2y-1=0 y=2 x=-2 x^y=4

x^2+y^2+xy-3y+3=0 即x^2+xy+y^2/4+3y^2/4-3y+3=0 有(x+y)^2+3(y/2-1)^2=0 所以x+y=0 y/2-1=0 y=2,x=-y=-2 于是x^y=(-2)^2=4

x^2+y^2=(x+y)^2-2xy = 9-4=5 (x-y)^2 = (x+y)^2-4xy =9-8 =1 x-y = 1 or -1

原方程式=(X-1)^2+(Y-1)^2+(X-1)(Y-1)这个我简单说明一下A=(X-1)B=(Y-1)原方程=a^2+b^2+ab=1/2{a^2+b^2+(a+b)^2}所以a=b=0即X=Y=1

由已知等式,令x=sin³θ,y=cos³θ x²+y² =(sin³θ)²+(cos³θ)² =(sin²θ)³+(cos²θ)³ =(sin²θ+cos²θ)(sin⁴θ-sin²θcos²θ+cos⁴θ) =(sin²θ+cos²...

1764804605 x二次方加y二次方的值

x^2-xy=-32xy-y^2=-82x^2+4xy-3y^2=2x^2-2xy+6xy-3y^2=2(x^2-xy)+3(2xy-y^2)=2×(-3)+3×(-8)=-30

x2+xy-2y2=0 (x-y)(x+2y)=0 x-y=0,x+2y=0 x=y或x=-2y x=y,则原式=(y2+3y2+y2)/(y2+y2)=5y2/2y2=5/2 x=-2y,则原式=(4y2-6y2+y2)/(4y2+y2)=-y2/5y2=-1/5

解:x²+xy=3 (1) xy+y²=-2 (2) (1)-(2),得 x²-y²=5即(x+y)(x-y)=5 (1)+(2),得 (x+y)²=1即(x+y)(x+y)=1 所以x+y=+-1 x-y=+-5 所以x=3,y=-2或x=-3,y=2 代入你要求得代数式即可求得值,因为“x加4xy加3y的二次方的...

12,第一个式子乘以2减去第二个式子乘以3得到12,望采纳!!!

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