Đáp án + giải thích các bước giải : $\\$ `e) x^2 - y^2 - 2x - 2y`
$\\$` = (x-y)(x+y) - 2(x+y)`
$\\$` = (x+y)(x-y-2)`
$\\$`g) x^2y^2 + 1 - x^2 - y^2 `
$\\$` = x^2y^2 - x^2 - (y^2 - 1)`
$\\$` = x^2 (y^2 -1) - (y^2 - 1)`
$\\$` = (y^2 - 1)(x^2 - 1)`
$\\$` = (y-1)(y+1)(x+1)(x-1)`
$\\$` h) x^2 + 2x -3`
$\\$` = x^2 +3x - x - 3`
$\\$` = x(x+3) - (x+3)`
$\\$` = (x-1)(x+3)`
$\\$` k) x^2 - 10x + 16`
$\\$ `= x^2 - 2x - 8x + 16`
$\\$` = x(x-2) - 8(x-2)`
$\\$` = (x-8)(x-2)`
