问题
解答题
计算:(1)[(3x+2y)2-(3x-2y)2+4xy]÷(-2x)
(2)3y(4x-3y)(3y+4x)-(2x-3y)(4x2+6xy+9y2)
答案
(1)[(3x+2y)2-(3x-2y)2+4xy]÷(-2x),
=[6x•4y+4xy]÷(-2x),
=-14y;
(2)3y(4x-3y)(3y+4x)-(2x-3y)(4x2+6xy+9y2),
=3y(16x2-9y2)-(8x3-27y3),
=48x2y-27y3-8x3+27y3,
=48x2y-8x3.