数学题因式分解9(x+2y)的平方-25(x-2

数学题因式分解9(x+2y)的平方-25(x-2y)的平方

2个回答

原式=[3(x+2y)]²-[5(x-2y)]²
=[3(x+2y)+5(x-2y)][3(x+2y)-5(x-2y)]
=(8x-4y)(-2x+16y)
=-8(2x-y)(x-8y)