If `a in Z` and the equation `(x-a)(x-10)+1=0` has integral roots, then values of `a` are

If a in Z and the equation (x-a)(x-10) +1=0 has integral roots then the values of a are

If a in Z and the equation (x-3)(x-a)+1=0 has integral roots, then the value of ' a ' are

If x^(2)-p x+q=0 has equal integral roots, then

Number of integral values of a for which the equation x^(2)-(a+1)x+a-1=0, has integral roots,is equal to -

Number of integral values of a for which the equation x^2-(a+1)x+a-1=0 , has integral roots, is equal to -

The number of integral values of a for which the quadratic equation (x+a)(x+1991)+1=0 has integral roots are a. 3 b. 0 c. 1 d. 2