B is definitely the answer
X= -10
You may review the image Ive attached to see how I got this answer.
Don't trust me but it's probably the first one. Just using context clues
Answer and workings can be found in the attachment below...
Answer:

Step-by-step explanation:
Given


c = hypotenuse
Required
Find c
Using Pythagoras theorem, we have:

Substitute values for a and b



Take square roots of both sides:

Express 20 as 4 * 5

Split surd

Take square root of 4

