(3x – 2) (x – 1) (3x + 5)
= {(3x – 2) (x – 1)} × (3x + 5) [∴Multiplication in associative]
= {3x (x – 1) – 2 x – 1)} × (3x + 5)
= (3x2 – 3x – 2x + 2) × (3x + 5)
= (3x2 – 5x + 2) (3x + 5)
= 3x2 × (3x + 5) – 5x (3x + 5) + 2 (3x + 5)
= (9x3 + 15x2) + (-15x2 – 25x) + (6x + 10)
= 9x3 + 15x2 – 15x2 – 25x + 6x + 10
= 9x3 – 19x + 10
