a^2+b^2-2a-2b+2ab+1+|ab+5|=0
(a+b-1)²+|ab+5|=0
a+b-1=0,ab+5=0
∴a+b=1,ab=-5
a²+b²=(a+b)²-2ab
=1²-2×(-5)
=11
(a-b)²=(a+b)²-4ab
=1²-4×(-5)
=21
∴a-b=±√21
a²-b²=(a+b)(a-b)=±√21
a^2+b^2-2a-2b+2ab+1+|ab+5|=0
(a+b-1)²+|ab+5|=0
a+b-1=0,ab+5=0
∴a+b=1,ab=-5
a²+b²=(a+b)²-2ab
=1²-2×(-5)
=11
(a-b)²=(a+b)²-4ab
=1²-4×(-5)
=21
∴a-b=±√21
a²-b²=(a+b)(a-b)=±√21