$2x^2 + 4x + 2 =$

$1 - m^2 =$

$m^2 + 1 =$

$2x^2 + 5x + 2 =$

$x^4 - 2x - 1 =$

$n^4 - 1n^2 + 25 =$

$x^2 + x + 1/4 =$

$z^2 - 2z + 4 =$

$(x^2 - y^2) + 4x + 4 =$

$8x^2 + 24xy + 18y^2 =$

$4x^2 + 7x + 2 =$

$4x^2 - 4y^2 =$