A four-sided polygon has sides that measure (2x + 1), (4x - 10), (x + 1) and (12x + 25). What is the perimeter of the polygon, in terms of x?

The perimeter would be found by adding all 4 of these expressions together, remembering that we can combine like terms. Here is what it would look like:

(2x+1) + (4x-10) + (x+1) + (12x+25). The bold parts are terms that can be combined together and all the other numbers (constants) can be combined.

2x+4x+1x+12x=19x

1 + (-10) + 1+25 = 17

19x+17 would be the simplified expression that represents the perimeter.