解方程:2x2-5x=0;
解方程:9x2-16=0;
方程x3+4x=0的解是________.
计算:(4mn-m2-4n2)÷(2n-m)=_________.
计算:(x2-xy+y2)÷(x-y)=________.
计算:(9a2-4b2)÷(3a-2b)=________.