Answer:
[tex]\$18[/tex]
Step-by-step explanation:
Let the cost of sheet metal per square feet be [tex]x[/tex]
Amount of sheet metal bought is [tex]10.8\ \text{ft}^2[/tex]
Amount of sheet metal used is [tex]3.7\ \text{ft}^2[/tex]
Remaining value of the sheet metal is [tex]\$127.8[/tex]
So we get the equation
[tex]10.8x-3.7x=127.8\\\Rightarrow 7.1x=127.8\\\Rightarrow x=\dfrac{127.8}{7.1}\\\Rightarrow x=18[/tex]
So, cost of sheet metal per square feet is [tex]\$18[/tex].