The whiteboard in the SPA has a perimeter of 408 inches. The length is 11 inches less than 4 times the height. How many inches high is the whiteboard?

Question

mathstudent55 · Answer

Let L = length and H = height

The perimeter of a rectangle is the sum of the lengths of all the sides.
P = L + L + H + H
408 = 2L + 2H
2L + 2H = 408 (this is one equation)

The following statement will gives us the other equation.
The length is 11 inches less than 4 times the height.
       L         =                                4H                          - 11
L = 4H - L (this is the second equation)

Now you need to solve the system of equations:
2L + 2H = 408
L = 4H - 11