Answer
composite, 2*2*5
Work Step by Step
Begin by selecting any two numbers, excluding 1 and 20, whose product is 20. Here is one possibility:
20 = 4*5
Because the factor 4 is not prime,
20 = 5*4 This is our first factorization.
20 = 2*2*5 Factor 4 .
Notice that 2 and 5 are both prime. The prime factorization of 20 is 2*2*5