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30 March, 21:50

A piece of cardboard in the shape of a parallelogram is twisted to form the tube for a roll of paper towels. The parallelogram has an area of 60 square inches. If its height h is 7 inches more than the length of the base b, what is the length of the base? (Hint: The formula for the area of a parallelogram is A = bh in

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  1. 30 March, 22:32
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    base = 5 in

    height = 12 in

    Step-by-step explanation:

    Area = base x height

    Base = b

    Height = b+7

    So:

    60 = b (b+7)

    60 = b^2 + 7b

    0 = b^2 + 7b - 60

    Applying quadratic formula:

    a = 1; b=7; c=-60

    For: ax2 + bx + c

    x = [ - b ± √b²-4ac] / 2a

    Replacing with the values given:

    x = [ - 7 ± √ (7) ²-4 (1) - 60] / 2 (1)

    x = [ - 7 ± √49 + 240] / 2

    x = [ - 7 ± √289] / 2

    x = [ - 7 ± 17] / 2

    Positive:

    x = [ - 7 + 17] / 2 = 5

    So:

    b = 5 in (base)

    Height = b+7 = 5+7 = 12 in

    Feel free to ask for more if needed or if you did not understand something.
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