【多项式相乘】:(3x-y)(y+3x)-(4x-3y)(4x+3y) 【要过程】Thanks!
问题描述:
【多项式相乘】:(3x-y)(y+3x)-(4x-3y)(4x+3y) 【要过程】Thanks!
答
(3x-y)(y+3x)-(4x-3y)(4x+3y)
=(3x-y)(3x+y)-(4x-3y)(4x+3y)
=(9x²-y²)-(16x²-9y²)
=9x²-y²-16x²+9y²
=-7x²+8y²