The mirror formula for curved mirrors is:

where
f is the focal length of the mirror

is the distance of the object from the mirror

is the distance of the image from the mirror
The sign convention that should be used in order to find the correct values is the following:
-

: positive if the mirror is concave, negative if the mirror is convex
-

: positive if the image is real (located on the same side of the object), negative if it is virtual (located on the opposite side of the mirror)
Answer: Glands
Explanation: Glands are the structures of the endocrine system that produce and secrete hormones.
The currency for performing work is called : Energy
And Energy's unit of measurement is : Joule
The amount of energy you've inputed will always equal the output.
For example, in order to do a 500 joules of work, you need 500 joules of energy