Answer:
45 cm
Step-by-step explanation:
Find LCM(15,9). First factor both numbers:
[tex]15=3\cdot 5\\ \\9=3\cdot 3[/tex]
So,
[tex]LCM(15,9)=3\cdot 5\cdot 3=45[/tex]
This means that the length of the side of the smallest square area that can be covered by these tiles is 45 cm.
Practically, you can put 3 tiles in a row (to make 3 lenghts of 15 cm each that add up to 45 cm) and put such 5 rows (to make 5 lengths of 9 cm that add up to 45 cm).
