(3X+2Y)*(4X+5Y)*(3X-2Y)*(5Y-4X) 等于多少?
问题描述:
(3X+2Y)*(4X+5Y)*(3X-2Y)*(5Y-4X) 等于多少?
答
(3X+2Y)*(4X+5Y)*(3X-2Y)*(5Y-4X)
=[(3X+2Y)(3X-2Y)]*[(5Y+4X)(5Y-4X)]
=(9X^2-4Y^2)(25Y^2-16X^2)
=-144X^4+289X^2Y^2-100Y^4