Answer:
The cost of the postage for the letter weighing 3 ounces will be $1.62
Step-by-step explanation:
From the question, we know that the first ounce will cost $0.22 and any additional ounces will cost $0.70, therefore, we can make the following equation where "c" is the total cost of the postage and "a" will be the total weight of the letter in ounces.
c = 0.22 + (0.70)(a - 1)
(we subtract 1 from "a" because for the first ounce we will pay $0.22 instead of $0.70)
Now we just solve the equation by substituting "a" with 3, and we get...
c = 0.22 + (0.70)(a - 1)
c = 0.22 + (0.70)(3 - 1)
c = 0.22 + (0.70)(2)
c = 0.22 + 1.40
c = $1.62
Therefore, the cost of the postage for the letter weighing 3 ounces will be $1.62.