已知1/2x-y=-3,求代数式[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除以4x的值_数学解答

已知1/2x-y=-3,求代数式[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除以4x的值

人气：301 ℃　时间：2019-08-17 18:23:13

解答

[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x
=(9x²-4y²-5x²-8xy+4y²)/4x
=(4x²-8xy)/4x
=x-2y
=2(1/2x-y)
=2×(-3)
=-6