It is equivalent because of the distributive property. If you multiply 4 by x and y, you get 4x and 4y.
4x + 4y = 4x + 4y
A functions is discontinuous if it has stuff like holes, jumps, or vertical asymptotic. In addition, it's continuous if it stays in a line the whole time (it doesn't have to be straight or anything!)
8 because 12-4=8. Im writing this part for the 20 characters
First step: Isolate the term that has x. To do that, subtract 2y from both sides.
Now divide both sides by 3.
The answer to the question is D