问题
填空题
若ab=2,a+b=5,(a+b)2=a2+2ab+b2,那么a2+b2+1=______.
答案
因为ab=2,a+b=5,
则a2+b2+1
=(a+b)2-2ab+1
=52-2×2+1
=25-4+1
=22.
故答案为:22,.
若ab=2,a+b=5,(a+b)2=a2+2ab+b2,那么a2+b2+1=______.
因为ab=2,a+b=5,
则a2+b2+1
=(a+b)2-2ab+1
=52-2×2+1
=25-4+1
=22.
故答案为:22,.