已知a2+2ab=-8,b2+2ab=14,则a2+4ab+b2=_;a2-b2=_.
问题描述:
已知a2+2ab=-8,b2+2ab=14,则a2+4ab+b2=______;a2-b2=______.
答
∵a2+2ab=-8,b2+2ab=14,
∴a2+2ab+b2+2ab=a2+4ab+b2=6,
a2+2ab-(b2+2ab)=a2-b2=-8-14=-22.
即:a2+4ab+b2=6,a2-b2=-22.