若a+b=-1/2,则2a^2+4ab+2b^2=?

问题描述:

若a+b=-1/2,则2a^2+4ab+2b^2=?

2a^2+4ab+2b^2=2(a^2+2ab+b^2)=2(a+b)^2=2*(-1/2)^2=2*1/4=1/2