Question

Find the cube root by prime factorization:

(i) 10648; (ii) 46656; (iii) 15625.

Answer 1

(i) 10648

= 2 × 5324

= 2 × 2 × 2662

= 2 × 2 × 2 × 1331

= 2 × 2 × 2 × 11 × 121

= 2 × 2 × 2 × 11 × 11 × 11

∴

(ii) 46656

= 2 × 23328

= 2 × 2 × 11664

= 2 × 2 × 2 × 5832

= 2 × 2 × 2 × 2 × 2916

= 2 × 2 × 2 × 2 × 2 × 1458

= 2 × 2 × 2 × 2 × 2 × 2 × 729

= 2 × 2 × 2 × 2 × 2 × 2 × 3 × 243

= 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3 × 3 × 3 × 3 × 3

∴

(iii) 15625

= 5 × 3125

= 5 × 5 × 625

= 5 × 5 × 5 × 5 × 5 × 5

∴