党的九大:(a+b)3=?请问(a+b)3立方,怎么算?
来源:百度文库 编辑:高校问答 时间:2024/05/30 19:18:18
(a+b)^3
=(a+b)^2×(a+b)
=(a^2+2ab+b^2)(a+b)
=a^3+a^2b+2a^b+2ab^2+2ab^2+b^3
=a^3+3a^2b+3ab^2+b^3
杨辉三角最简单的应用,
=a^3+3(a^2)b+3a(b^2)+b^3
(a+b)^3
=(a+b)^2*(a+b)
=(a^2+2ab+b^2)*(a+b)
=a^3+a^2b+2a^b+2ab^2+ab^2+b^3
=a^3+b^3+3a^2b+3ab^2
(a+b)3=a^3+b^3+3a^2b+3ab^2
=a^3+3a^2b+3ab^2+b^3