(-2Y+3X)(-2-3X)怎么算?
问题描述:
(-2Y+3X)(-2-3X)怎么算?
答
(-2Y+3X)(-2-3X)
=(-2Y)(-2-3Y)+3X(-2-3Y)
=4Y+6Y^-6X-9XY
=6Y^+(4-9X)Y-6X
答
(-2Y+3X)(-2-3X)
=-2Y(-2-3X)+3X(-2-3X)
=4Y+6XY-6X-9X^2
或者你的题目是(-2Y+3X)(-2Y-3X)
则由平方差
=(-2Y)^2-(3X)^2
=4Y^2-9X^2