若△ABC与△A′B′C′相似,一组对应边的长为AB=6cm,A′B′=8cm,那么△ABC与△A′B′C′的相似比为________.
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)=________.
计算:(2x2-4xy)÷(x-2y)=________.