The value of (a-1) + a^2-b^2/1-ab+2 (a-b) / 2b when a=2 and b=-1 is?

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