(x+3y)(x-3y)(x的平方-9y的平方)

问题描述:

(x+3y)(x-3y)(x的平方-9y的平方)

(x+3y)(x-3y)(x的平方-9y的平方)
=(x^2-9y^2)(x^2-9y^2)
=(x^2-9y^2)^2

(x+3y)(x-3y)(x²-9y²)
=(x²-9y²)(x²-9y²)
=(x²-9y²)²
=x⁴-18x²y²+81y⁴