(1/3)k(4k^2-1)+(2k+1)^2为什么=(1/3)(k+1)[4(k+1)^2-1]要什么公式?求详解

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/25 15:41:44
(1/3)k(4k^2-1)+(2k+1)^2为什么=(1/3)(k+1)[4(k+1)^2-1]要什么公式?求详解

(1/3)k(4k^2-1)+(2k+1)^2为什么=(1/3)(k+1)[4(k+1)^2-1]要什么公式?求详解
(1/3)k(4k^2-1)+(2k+1)^2为什么=(1/3)(k+1)[4(k+1)^2-1]
要什么公式?求详解

(1/3)k(4k^2-1)+(2k+1)^2为什么=(1/3)(k+1)[4(k+1)^2-1]要什么公式?求详解
(1/3)k(4k^2-1)+(2k+1)^2
=(1/3)k(2k-1)(2k+1)+(2k+1)^2
=(1/3)(2k+1)[ k(2k-1) +3(2k+1) ]
=(1/3)(2k+1)(2k^2+5k+3)
=(1/3)(2k+1)(2k+3)(k+1)
=(1/3)(k+1)( 4k^2+8k+3 )
=(1/3)(k+1)( 4(k+1)^2 -1)

(1/3)k(4k^2-1)+(2k+1)^2
=(1/3)k(2k-1)(2k+1)+(2k+1)^2
=(1/3)(2k+1)[k(2k-1)+3(2k+1)]
=(1/3)(2k+1)(2k^2+5k+3)
=(1/3)(2k+1)(2k+3)(k+1)

(1/3)(k+1)[4(k+1)^2-1]
=(1/3)(k+1)[2(k+1)-1][2(k+1)+1]
=(1/3)(k+1)(2k+1)(2k+3)