已知关于x的一元二次方程x2+(2m-3)x+m2=0的两个不相等的实数根α,β满足+=1,则m的值是 ;
计算:(m-n)(m+n)=________;
计算:m-n-(m+n)=_________;
计算:51×49=_________.
(1)(3a-4b)()=9a2-16b2;(2)(4+2x)()=16-4x2; (3)(-7-x)()=49-x2;(4)(-a-3b)(-3b+a)=_______.
计算: (1)(a+1)(a-1)=_________;(3)(-a+1)(a+1)=________; (3)(-a+1)(a+1)=________;(4)(a+1)(-a-1)=_______.