Respuesta :

Take into account that the total area of the two rooms are:

A = 28 + 63 = 91

You can notice that the following expressions also result in 91:

7(4 + 9) = 7(13) = 91

7*4 + 7*9 = 28 + 63 = 91

Then, the answer is:

7(4 + 9)

7*4 + 7*9