2x²-3xy-y²
=2x²+9x²/4-9x²/4-3xy-y²
=2x²+9x²/4-(9x²/4+3xy+y²)
=17x²/4-(3x/2+y)²
=[(√17x/2-(3x/2+y)][(√17x/2+(3x/2+y)]
=(√17x/2-3x/2-y)(√17x/2+3x/2+y)
2x²-3xy-y²
=2x²+9x²/4-9x²/4-3xy-y²
=2x²+9x²/4-(9x²/4+3xy+y²)
=17x²/4-(3x/2+y)²
=[(√17x/2-(3x/2+y)][(√17x/2+(3x/2+y)]
=(√17x/2-3x/2-y)(√17x/2+3x/2+y)