Find the expansion of

(p + 2)(p – 4)(p + 6)

(p + 2)(p – 4)(p + 6)

Here the identity used is

(x + a)(x + b)(x + c) = x³ + (a + b + c)x² + (ab + bc + ca)x + abc

∴ (p + 2)(p – 4)(p + 6)

= p³ + (2 – 4 + 6) p² + (2(– 4) + (– 4)6 + 6(2))p + (2)(– 4)(6)

= p³ + 4p² + (– 8 – 24 + 12)p – 48

= p³ + 4p² – 20p – 48