3x^2(x^3+5) 7x(x-4)-x(x-6) (x-1)(3x-5) a^4-a^3 8a^4b-36a^3b^6 2x(a+b)-y(a+b) 5(c-d)-m(d-c) ay-3y-4a+12 x^2-4x-5 !

3x²(x³ + 5) = 3x⁵ + 15 x²
7x(x - 4) - x(x - 6) = 7x² - 28x - x² + 6x = 6x² - 22x
(x - 1)(3x - 5) = 3x² - 5x - 3x + 5 =3x² - 8x + 5
a⁴  - a³ = a³(a - 1)
8a⁴ b - 36a³b⁶ = 4a³b(2a - 9b⁵)
2x(a + b) - y(a + b) = (a + b)(2x - y)
5(c - d) - m(d - c) = 5(c - d) + m(c - d) = ( c - d)(5 + m)
ay - 3y - 4a + 12 = (ay - 3y) - (4a - 12) = y(a - 3) - 4(a - 3) = (a - 3)(y - 4)
x² - 4x - 5 = x² - 1 - 4x - 4 = ( x² - 1) - (4x + 4) = (x - 1)(x + 1) - 4(x + 1) =
 = (x + 1)( x - 1 - 4) =(x + 1)(x - 5)