Answer:
5
Step-by-step explanation:
Find the complete question attached
The factor of 90 is as shown;
2 | 90
3 | 45
3 | 15
5 | 5
| 1
Hence the prime factorization of 90 is 2 * 3 * 3 * 5
90 = 2 * 3² * 5
The number that completes the prime factorization is 5
