3a^3c^2 + 6a^3c^2 - 9a^3c^3 = 3a^3c^2 (1 +2 - 3c) = 3a^3c^2(3 - 3c)
a(x +y) + a(b -x) = a(x + y + b - x) = a(y + b)
(a - b)^3 - a(a - b)^2 = (a - b)^2 * (a - b - a) = - b(a - b)^2
6x^2(x - y) - 3x(x - y)^2 = 3x(x - y)*(2x - x + y) = 3x(x - y) * (x + y)
2x + 3xy = x(2 + 3y)
5ab + 10a^2 = 5a(b + 2a)
a^4 + a^3 = a^3(a + 1)
xy^3 + 5x^2y = xy(y^2 + 5x)
2 - 3x^2y
x(a + c) - x(a + b) = x(a + c - a - b) = x(c - b)
a(a - y)^2 + (y - a)^3 = a(a - y)^2 - (a - y)^3 = (a - y)^2 *(a - a + y) = (a - y)^2 * y
3a(a - b)^2 + 9a^2(a - b) = 3a(a - b) * (a - b + 3a) = 3a(a - b) * (4a - b)