Question: Find the product:
(3x2 + 5x − 9) × (3x − 5)
Solution:
By horizontal method:
$\left(3 x^{2}+5 x-9\right) \times(3 x-5)$
$=3 x\left(3 x^{2}+5 x-9\right)-5\left(3 x^{2}+5 x-9\right)$
$=9 x^{3}+15 x^{2}-27 x-15 x^{2}-25 x+45$
$=9 x^{3}-52 x+45$
