已知a²+b²+2a-4b+5=0,则a²-2ab-3b²/a(a-b)+3ab+b²的值为?
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![已知a²+b²+2a-4b+5=0,则a²-2ab-3b²/a(a-b)+3ab+b²的值为?](/uploads/image/z/4614604-52-4.jpg?t=%E5%B7%B2%E7%9F%A5a%26%23178%3B%2Bb%26%23178%3B%2B2a-4b%2B5%3D0%2C%E5%88%99a%26%23178%3B-2ab-3b%26%23178%3B%2Fa%28a-b%29%2B3ab%2Bb%26%23178%3B%E7%9A%84%E5%80%BC%E4%B8%BA%3F)
已知a²+b²+2a-4b+5=0,则a²-2ab-3b²/a(a-b)+3ab+b²的值为?
已知a²+b²+2a-4b+5=0,则a²-2ab-3b²/a(a-b)+3ab+b²的值为?
已知a²+b²+2a-4b+5=0,则a²-2ab-3b²/a(a-b)+3ab+b²的值为?
a²+b²+2a-4b+5=0
a^2+2a+1+b^2-4b+4=0
(a+1)^2+(b-2)^2=0
则a+1=0
b-2=0
的a=-1,b=2
则
a²-2ab-3b²/a(a-b)+3ab+b²
=(a²-2ab-3b²)/(a^2+2ab+b²)
=(a²-2ab+b^2-4b²)/(a+b)^2
=((a-b)^2-4b²)/(a+b)^2
=(-1-2)^2-4*2^2/(-1+2)^2
=(9-16)/1
=-7