I probably have this totally wrong but -10?
Answer:
<u>yes your formula is correct </u>
Step-by-step explanation:
Example:

This suggests two solutions,

and

.
However, upon plugging these solutions back into the equation, you get

which checks out, but

does not because

is defined only for

(assuming you're looking for real solutions only). So, we call

an extraneous solution, and the complete solution set (over the real numbers) is

.
Answer:
top right
Step-by-step explanation:
If you imagine yourself building with that model you can see its that one