Question

Using prime factorization method, find which of the following numbers are perfect square? 

189, 

Answer 1

189 = 3 x 3 x 3 x 7 

 

Grouping them into pairs of equal factors:
189 = (3 x 3) x 3 x 7
The factors 3 and 7 cannot be paired. Hence, 189 is not a perfect square.