It’s gonna be all real numbers (-infinity, infinity) because it goes through all the points. And because there’s no restrictions
I don’t understand your question can you go into more detail please
A is your answer 3.4
Use Pythagorean Theroum
10.2 squared = 9.6 squared + x squared
104= 92.6+x squared
x squared = 11.4
x= 3.37
round x to 3.4
Hope that helps!