The answer is: [D]: " 24 + 2w " .
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Explanation:
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Given: The formula for the Perimeter of a rectangle:
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P = 2L + 2w ;
in which:
P = perimeter ;
L = length = 12 units (given);
w = width = unknown;
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Find the perimeter, "P", in terms of "w" ; since "w" (width) is unknown; and considering the answer choices given; along with the information provided in the problem, we only have enough information to solve for the perimeter, "P", in terms of "w" ;
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So, given the formula/equation for the perimeter, "P" :
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P = 2L + 2w ; we know that: " L = 12 units " ;
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P = 2*12 + 2w = 24 + 2w ; which is: "Answer choice: [D]" .
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