Question

Determine the prime factorization of 90

Answer 1

a 2 • 3^2• 5

b 2^2• 3 • 5

c 2^3• 11

d 2^2• 11

Answer 2

Break it down to smaller numbers: 90 = 9 * 10, so prime-factor 9 and 10.

90 = 9 * 10 = 3 * 3 * 2 * 5 = 2 * 3^2 * 5

So the prime factors of 90 are 2, 3 (twice, or squared), and 5.