1,若x不等于0是x^2+xy+y^2=0,则(x^2+3xy+y^2)/(x^2+y^2)=?2.因式分解:4x^4-13x^2+93.因式分解:(x^2-2x)^2-7(x^2-2z)+12
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![1,若x不等于0是x^2+xy+y^2=0,则(x^2+3xy+y^2)/(x^2+y^2)=?2.因式分解:4x^4-13x^2+93.因式分解:(x^2-2x)^2-7(x^2-2z)+12](/uploads/image/z/14654590-70-0.jpg?t=1%2C%E8%8B%A5x%E4%B8%8D%E7%AD%89%E4%BA%8E0%E6%98%AFx%5E2%2Bxy%2By%5E2%3D0%2C%E5%88%99%28x%5E2%2B3xy%2By%5E2%29%2F%28x%5E2%2By%5E2%29%3D%3F2.%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%EF%BC%9A4x%5E4-13x%5E2%2B93.%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%EF%BC%9A%EF%BC%88x%5E2-2x%EF%BC%89%5E2-7%28x%5E2-2z%29%2B12)
1,若x不等于0是x^2+xy+y^2=0,则(x^2+3xy+y^2)/(x^2+y^2)=?2.因式分解:4x^4-13x^2+93.因式分解:(x^2-2x)^2-7(x^2-2z)+12
1,若x不等于0是x^2+xy+y^2=0,则(x^2+3xy+y^2)/(x^2+y^2)=?
2.因式分解:4x^4-13x^2+9
3.因式分解:(x^2-2x)^2-7(x^2-2z)+12
1,若x不等于0是x^2+xy+y^2=0,则(x^2+3xy+y^2)/(x^2+y^2)=?2.因式分解:4x^4-13x^2+93.因式分解:(x^2-2x)^2-7(x^2-2z)+12
1,
x^2+xy+y^2=0 则
x^2+3xy+y^2
=(x^2+xy+y^2)+2xy
=0+2xy
=2xy
x^2+y^2
=(x^2+xy+y^2)-xy
=0-xy
=-xy
则
(x^2+3xy+y^2)/(x^2+y^2)
=2xy/-xy
=-2
-----------------------------
2,
4x^4-13x^2+9
=(x^2-1)(4x^2-9)
=(x-1)(x+1)(2x-3)(2x+3)
--------------------------
3,(楼主:z应改成x)
(x^2-2x)^2-7(x^2-2x)+12
=(x^2-2x-4)(x^2-2x-3)
=(x^2-2x-4)(x-3)(x+1)
1,若x不等于0是x^2+xy+y^2=0,则(x^2+3xy+y^2)/(x^2+y^2)=?
x^2+y^2=-xy
(x^2+3xy+y^2)/(x^2+y^2)=-2
2.因式分4x^4-13x^2+9
=(4x^2-9)(x^2-1)
=(2x+3)(2x-3)(x+1)(x-1)
3.因式分(x^2-2x)^2-7(x^2-2z)+12
大虾帮帮忙啊~~~~
=(x^2-2x-3)(x^2-2x-4)
=(x-3)(x+1)(x^2-2x-4)
分解x^2+xy-2y^2=0,(x+2y)(x-y)=0,x=-2y或 x=y
(x^2+3xy+y^2)/(x^2+y^2)
=「(x^2+xy-2y^2)+(2xy+3y^2)」/(x^2+y^2)
=(2xy+3y^2)/(x^2+y^2)
将x=-2y ,x=y分别代入 可得
原式=-1/5或5/2