(1)5x^2-5x-60
=5(x²-x-12)
=5(x+3)(x-4)
（2)2X^3-8X^2-24x
=2x(x²-4x-12)
=2(x-6)(x+2)
（3）2a^2b^2+14ab-60
=2(a²b²+7ab-30)
=2(ab+10)(ab-3)
（4）x^3-8x^2y-20xy^2
=x(x²-8xy-20y²)
=x(x+2y)(x-10y)