Find the values of m and n if the following expression are perfect squares.
`x^(4)-8x^(3)+mx^(2)+nx+16`

Find the values of m and n if the following expression are perfect squares. (1)/(x^(4))-(6)/(x^(3))+(13)/(x^(2))+(m)/(x)+n

Find the values of a and b if the following polynomials are perfect squares 4x^(4)-12x^(3)+37x^(2)+bx+a

Find the values of a and b if the following polynomials are perfect squares ax^(4)+bx^(3)+361ax^(2)+220x+100

Find the excluded values, if any of the following expressions (x^(3)-27)/(x^(3)+x^(2)-6x)