Explanation:
The square root of a number is whatever number times itself equals the main number. 
For example: 
The square root of 144 is 12, because 12*12=144. 
Firstly, let's find the square root of 25. This is 5, because 5x5=25. 
Next, let's find the square root of 40. This is about 6.32. 
Now, let's find the square root of 90. This is about 9.48. 
Next, let's add these numbers together. (5 + 6.32 + 9.48 = 20.8). 
Finally, we need to simplify. The end result will be 104/5.