(a+b/3)²-(a-b/3)²,其中a=22/3,b=81/44
问题描述:
(a+b/3)²-(a-b/3)²,其中a=22/3,b=81/44
答
(a+b/3)²-(a-b/3)²
=a²+2ab/3+b²/9-(a²-2ab/3+b²/9)
=a²+2ab/3+b²/9-a²+2ab/3-b²/9
=4ab/3
=2