若a+b=2,b+c=3则(a+2b+c)^2-(a-c)^2的值为
问题描述:
若a+b=2,b+c=3则(a+2b+c)^2-(a-c)^2的值为
答
a+b=2,b+c=3
则,a-c= -1
(a+2b+c)^2-(a-c)^2
=(a+b+b+c)²-(a-c)²
=(2+3)²-(-1)²
=25-1
=24