The greatest possible value is 6.3
Using the pythagoras theorem
c² = a²+b²
20² = x² + 3x²
400 = 4x²
Divide through the equation by 4
x² = 100
x = √100
x = 10
The question asked for the greatest possible value = 6.3
6.3 is the highest possible value because no matter any other number we choose in the options there would be another one that is higher than it.
Therefore the greatest possible value is 6.3
Read more on Pythagorean theorem here: https://brainly.com/question/22568405
