Answer:180
Explanation:
you start by finding the prime factorization of the number
5=1*5
9=3*3
12=2*2*3
the shortest way to find the factors is to find is most of them like example, at max, there are 2 two's, 2 three's and 1 five then you multiply them all together
4*9*5=180 and that's the answer