Answer:
[tex] 3\sqrt{5} [/tex]
Step-by-step explanation:
Find the largest factor of 45 that is a perfect square.
The factors of 45 are 1, 3, 5, 9, 15, 45.
The largest perfect square is 9.
Now breakup 45 into a product which has 9 as a factor.
45 = 9 * 5
[tex] \sqrt{45} = \sqrt{9 \times 5} = \sqrt{9} \times \sqrt{5} = 3\sqrt{5} [/tex]