3(n-1)²-2(n-1)+1怎么化简
问题描述:
3(n-1)²-2(n-1)+1怎么化简
答
3(n-1)²-2(n-1)+1
=3(n²-2n+1)-2(n-1)+1
=3n²-6n+3-2n+2+1
=3n²-8n+63(n²-2n+1)看不懂(n-1)²=n²-2n+1