题目多项式2xmyn−1−4xm−1yn(m2x^{m}y^{n-1}-4x^{m-1}y^{n}(m2xmyn−1−4xm−1yn(m,nnn均为大于111的整数）各项的公因式是（ ）A.4xm−1yn−14x^{m-1}y^{n-1}4xm−1yn−1B.2xm−1yn−12x^{m-1}y^{n-1}2xm−1yn−1C.2xmyn2x^{m}y^{n}2xmynD.4xmyn4x^{m}y^{n}4xmyn知识点：公因式章节：数与式 / 因式分解
