Respuesta :

mathstudent55
Since 5.50 is being added to 27.75n, you need to undo the addition.
Subtraction is the opposite operation to addition.
Subtract 5.50 from both sides.

27.75n + 5.50 = 144.25
            - 5.50       -5.50
-------------------------------
27.75n            = 138.75