Question

一个长方体的长是a米，宽是b米,高是h米，如果高增加了3米，长减少1米，体积增加多少立方米？

急急急急急急急急急

Answer 1

(a-1)*b*(h+3)-a*b*h
=ab(h+3)-b(h+3)-abh
=abh+3ab-bh-3b-abh
=3ab-bh-3b

Answer 2

(h+3)*(a-1)*b=abh-bh+3ab-3b
abh-bh+3ab-3b-abh=-bh+3ab-3b
答：体积增加-bh+3ab-3b立方米

Answer 3

(a-1)*b*(h+3)-a*b*h =-bh-3b+3ab