Given that total amount of metal in the beginning = 8.2 square feet
Given that used amount of metal = 2.1 square feet
Then remaining amount of metal = (8.2-2.1) = 6.1 square feet
Now it says that "$183 worth of sheet metal remaining".
That means cost of 6.1 square feet is $183.
Let cost of 1 square feet of the metal = x
Then cost of 6.1 square feet of the metal = 6.1x
Both expressions 6.1x and $183 represent the cost of the remaining metal so the required equation will be:
6.1x=183
Now we can solve it to find the solution
x=183/6.1
x=30
So the cost per square feet of the metal = $30
Answer : Hence final answer is $30 per square feet.