Answer:
A=60
Step-by-step explanation:
Add 28+20+12
A=60
I think the second one is correct
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

.
You put the 0 if it is close to 0, the 1/2 if it is closer to half, 1 if it is equal or closer to one, and the >1 if it is over one
Answer:
10 ft above sea level
Step-by-step explanation:
20 below goes up by 30 then it would be -20 -10 0 10