化简:4a(a﹣1)2﹣a(2a+5)(2a﹣5).
解:原式=4a(a2﹣2a+1)﹣a(4a2﹣25),
=4a3﹣8a2+4a﹣4a3+25a,
=﹣8a2+29a.
--- This is my treat and next is yours. How’s that?
---- OK. _______.
A.It doesn’t matter
B.It depends
C.No way
D.It’s a deal
天然土层在历史上所经受过的最大固结压力,称为前期固结压力。