A rectangle has length 2x+3 and width 7x+9. Write a polynomial in standard form that represents the perimeter of the rectangle. You MUST combine like terms.

18x+21

Step-by-step explanation:

First multiply each equation by 2 since there is 2 sides for both the length and width.

2(2x+3)   2(7x+9)

4x+3         14x+18    

Then combine like terms

4x+14x       3+18

18x              21