18р³ k⁶ 3k
------- * ----------- = ----------
k⁵ 24р⁵ 4p²
5a⁸ a²+6a+9 5a⁸ *(a+3)² a⁴*(a+3)
----------- * -------------- = --------------------- = ----------------
3+a 15a⁴ (3+a)15a⁴ 3
4y²-1 y+3 (2y-1)*(2y+1)*(y+3) 2y-1
---------- * ----------- = ------------------------------- = -----------
y²-9 6y+3 (y-3)*(y+3)*3*(2y+1) 3*(y-3)