Answer:
Hence, the total cost of mailing 10 ounces is:
$ 2.52
Step-by-step explanation:
If postage costs $.54 for the first ounce and $.22 for the each additional ounce.
i.e. cost of first ounce=$ 0.54.
Now let x denote the number of ounces after the first ounce,
Hence, the cost of x ounces=$ (0.22×x)=$ 0.22 x
Hence, the cost of mailing (x+1) ounces is: $ (0.54+0.22 x)
Now, we have to find the cost of mailing a 10- ounce envelope.
i.e. after the first ounce we need 9 more ounces.
Hence, the total cost of mailing is calculated as:

Hence, cost of mailing 10 ounces is:
$ 2.52