Answer:
C = 3 √ 5
(since 9 is a perfect square), we can simplify radical 45 to 3 times radical 5
B √ 9*5 is true but not simplified.
We need to find a square numbers that divide into 45
We find 9
And show a * b = c
c= 45
so a * b = 9 * 5 = 3√ 5 is how we arrange this to simplify.
Explanation:
The list is
1, 4, 9, 16, 25, 36, 49, 64, 81, 100
We see there are 10 perfect squares 1-100
5 are 1-25
then think 6 , 7, 6 , 9 ,10 squared/ if you cant list them too quickly.