(紧急)数学题:已知a²+2a+b²-4b+5=0,求2a²+4b-3的值

问题描述:

(紧急)数学题:已知a²+2a+b²-4b+5=0,求2a²+4b-3的值

a²+2a+b²-4b+5=0
(a²+2a+1)+(b²-4b+4)=0
(a+1)²+(b-2)²=0
a+1=0,b-2=0
a=-1,b=2
2a²+4b-3
=2×1+8-3
=7