早教吧 育儿知识 作业答案 考试题库 百科 知识分享

1.5a^2-5b^2-3a-3b2.9a^2-b^2-6bc-9c^2a^n*b^(n+2)-a^(n+2)*b^n

题目详情
1.5a^2-5b^2-3a-3b
2.9a^2-b^2-6bc-9c^2
a^n*b^(n+2)-a^(n+2)*b^n
▼优质解答
答案和解析
1 =5a^2-3a-(5b^2+3b)
=a(5a+3)-b(5b+3)
=(a-b)(5a+3)(5b+3)
2 =9a^2-(b^2+6bc+9c^2)
=9a^2-(b+3c)^2
3 =a^nb^n(b^2-a^2)