化简求值:已知x-2y=2013,求【(3x+2y)(3x-2y)-(x+2y)(5x-2y)】/4x的值
问题描述:
化简求值:已知x-2y=2013,求【(3x+2y)(3x-2y)-(x+2y)(5x-2y)】/4x的值
答
原式=(9x^2 - 4y^2 - 5x^2 - 8xy + 4y^2)/4x
= (4x^2 - 8xy )/4x
=4x (x-2y) /4x
=x-2y =2013