Answer:
w=4
Explanation:
The surface area of a prism is SA= 2lw+2lh+2hw
We are trying to find out the width if the SA is 240 square inches, length is 12 inches, and the height is 5 inches. Let's plug these numbers into the equation.
240=(2*12*w)+(2*12*5)+(2*5*w)
24w+120+10w
240= 34w+120
-120 -120
120= 34w
120/34 = 34w/34
w is approximately equal to 3.5 which can be rounded to 4
w=4
Hope this is right! It was confusing at first but I understood it!