Use multiple steps formula.
Answer:

Step-by-step explanation:

Expand brackets.


Apply radical rule : 


I think it’s C because 20-11 is C xD
Answer:
4.5
Step-by-step explanation:
There is a formula for the Intersection of chords
10*x = 9*5
here.
so.... x = 45/10 = 4.5
The answer is x=8 your welcome