Which of the following is a characteristic of a plane

I think you meant to add a list of answers but didn't so here's the characteristics of a plane: Flat, two dimensional, extends infinitely, and is assembled about multiple points and lines.

Step-by-step explanation:

You need to get rid of the parenthesis first and the work out to isolate p.

Step-by-step explanation:

You will first need to apply distributive to get rid of parethensis.

-3p -21 = 4 -6p -18

Now you need to bring all the p's to one side of the equation

-3p +6p = 4 -18 +21

add everything you can up

3p = 7

now take the 3 to the other side dividing

p = 7/3