①(m-n)³+2n(n-m)²因式分解 ②（2x²-2x+1/2)/(x-1/2)因式分解 ③已知a+b=-2,ab=-5/2,求a(a+b)(a-b)-a(a+b)²

①(m-n)³+2n(n-m)²因式分解 ②（2x²-2x+1/2)/(x-1/2)因式分解 ③已知a+b=-2,ab=-5/2,求a(a+b)(a-b)-a(a+b)²
①(m-n)³+2n(n-m)²因式分解 ②（2x²-2x+1/2)/(x-1/2)因式分解 ③已知a+b=-2,ab=-5/2,求a(a+b)(a-b)-a(a+b)²

①(m-n)³+2n(n-m)²因式分解 ②（2x²-2x+1/2)/(x-1/2)因式分解 ③已知a+b=-2,ab=-5/2,求a(a+b)(a-b)-a(a+b)²
①(m-n)³+2n(n-m)²=(m-n)³+2n(m-n)²=(m-n)²(m-n+2n)=(m-n)²(m+n)
②（2x²-2x+1/2)/(x-1/2) =(4x²-4x+1)/(2x-1)=(2x-1)²/(2x-1)=2x-1
③ a(a+b)(a-b)-a(a+b)² =a(a+b)(a-b-a-b)=-2ab(a+b)=-2*(-5/2)*(-2)=-10