Explain the difference betweena theory and a
law.

Theories are ideas and supposition used to explain something, a law is a system of rules in place to regulate actions of their members.  Theories are something that can be bent and changed at will. Laws have to be judged in court before someone can change them.

to figure the total magnification of an image that you are viewing through the microscope is really quite simple. to get the total magnification take the power of the objective (4x, 10x, 40x) and multiply by the power of the eyepiece, (usually 10x)

the statements that apply here about binary star system are

"have stars that might appear to wobble"

"often have one star that is brighter than other"

a binary star is a star system consisting of two stars revolving around their common barycenter. systems of two or more stars are called multiple star systems.