The value of (a-1)+a^2-b^2/1-ab+2(a-b)/2b when a=2 and b=-1 will be evaluated as follows:
substituting the values in the expression we obtain:
(2-1)+2^2-(-1)^2/1-(2*(-1))+2(2-(-1))/(2(-1))
simplifying the above we get:
1+4-1/1-(-2)+2(2+1)/(-2)
=1+4-1+2(3)/(-2)
=1+4-1-3
=5-4
=1
Answer: 1