Use Pythagorean Theorem which states that in a right triangle:

, where a and b are the legs, and c is the hypotenuse.

Take the square root of both sides to solve for x.

The answer is 26.
8x^2+10x-18
The explanation is in the picture below if needed
Y=4 or -4
Explanation: trust me bro
No it does not because a x-intercept repeats itself. Hopefully this helps
Step-by-step explanation:
I am not sure about the answer of (b). Hope it helps :)