Question

已知a(a-1)-( a^2-b)=1求代数式1/2（a^2+b^2)-ab)的值

Answer 1

a(a-1)-( a^2-b)=1

=a^2-a-a^2+b=1

b-a=1

1/2（a^2+b^2)-ab

=(1/2)(a-b)^2

=(1/2)*1^2

=1/2