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
