计算：(u-v)^2-uv 1/4x^2-(1/2x-y)(1/2x+y) 因式分解：-10xy+25x^2+y^2 2)2x^2+5x-3 3)x^4-6x^
计算：(u-v)^2-uv 1/4x^2-(1/2x-y)(1/2x+y) 因式分解：-10xy+25x^2+y^2
2)2x^2+5x-3 3)x^4-6x^2+8 4)(x^2-y^2)-(x-y)^2 5)x^2n+2-4x^2x 6)(x^2+y^2)^2-4x^2y^2 7)(x+y)^2+2(x^2-y^2)+(x-y)^2 8)x^4-5x+4 9)x^3+2x^2-63x