Question 198672
A rectangular light-switch plate is made according to the following dimensions. The length is 8 inches, and the width is 6 inches; a rectangular hole measuring 1 inch by 3 inches is left in the center. (See diagram below) (a) How many square inches in area is the light-switch plate (the shaded region)? (b) If the cost to construct the plate is $3.50 per square inch, what is the construction cost?
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a)
"area of light-switch plate" = "area of plate" - "rectangular hole" 
"area of light-switch plate" = (8)(6) - (1)(3)
"area of light-switch plate" = 48 - 3
"area of light-switch plate" = 45 square inches 
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b)
cost = 45*3.50 = $157.50