1.2a²b(x+y)²(b+c)-6a³b²(x+y)(b+c)²
=2*a^2*b*(x+y)*(b+c)[x+y-3ab(b+c)]
=2a^2b(x+y)(b+c)[x+y-3ab^2-3abc]
2.32ac²+15cx²-48ax²-10c³
=(32ac^2-10c^3)+(15cx^2-48ax^2)
=2c^2(16a-5c)+3x^2(5c-16a)
=2c^2(16a-5c)-3x^2(16a-5c)
=(16a-5c)(2c^2-3x^2)
3.3x³+7x²-4
=3x^3+(6x^2+x^2)-4
=(3x^3+6x^2)+(x^2-4)
=3x^2(x+2)+(x+2)(x-2)
=(x+2)(3x^2+x-2)
=(x+2)(x+1)(3x-2)