We know that
• The new charge was $0.50 to mail a letter weighing up to 1 ounce, and $0.21 for each additional ounce.
Based on the given information, the expression is

Where <em>x</em> represents additional ounces, and <em>y</em> represents a cost.
<h2>Hence, the function is</h2>
The answer is c because every quadrilateral adds up to 360 so when you add all the numbers you get 290 and when you subtract 360-290 is 70.