Solve equations

Question

the permittee of a rectangle is 18x+6. The width of the rectangle is 2x+5. what is an expression for the length of the rectangle? 

Answer 1

P = 18x + 6

 

P = 2W + 2L

 

If w = 2x + 5, then 2w = 4x +10

 

2L = P - 2W

 

18x + 6 - (4x +10) = 14x -4

 

2L = 14x - 4

 

L = 7x - 2

 

7x - 2 + 7x - 2 + 2x + 5 + 2x + 5 = 18x + 6