4(m+1)^2-(1+2m)(2m-1)

问题描述:

4(m+1)^2-(1+2m)(2m-1)

4(m+1)^2-(1+2m)(2m-1)
=4(m^2+2m+1)-(4m^2-1)
=4m^2+8m+4-4m^2+1
=8m+5