Question

5,21=2. 6,20=4. 8,55=?​

Answer 1

Step-by-step explanation:

5 , 21 = √(5)²-21 = √25-21 = √4 = 2

6 , 20 = √(6)²-20 = √36-20 = √16 = 4

The same way ,

8 , 55 = √(8)²-55 = √(64-55) = √9 = 3