Answer:
Optical axis
Step-by-step explanation:
Optical axis is the rotational symmetry axis of the surfaces.
A line with a certain degree of rotational symmetry is called as the optical axis in an optical system.
It is the straight line that passes through the geometric center of the lens and joins two curvature centers of its surfaces.
It is also called as the principal axis.
A break even problem is found when you calculate starting a buisieness
so lets ssay you have to buy 3 coppy machines and each machine costs 2000 dollars,
the people who want to use your coppy machines have to pay $0.40 per page
so you have spent 6000 dollars already
when you break even, it is when your earnings equals your expenditure (how much you earned equals how much you paid)
I hope this helps you
6y=13-2x
y=13-2x/6
y=13/6-1/3x
The third one is correct.....so go for it without hesitation
