algebra

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a rectangle is 4 times as long as it is wide. a second triangle is 5 centimeters longer and 2 centimeters wider than the first. the area of the second rectangle is 270 square centimeters greather than the first. what are the dimensions of the original rectangle? how would i solve this question?

  • algebra -

    first triangle : x by 4x
    second triangle : 4x+5 by x+2

    area of first = x(4x)
    area of second = (4x+5)(x+2)

    so (4x+5)(x+2) - x(4x) = 270

    solve for x, you should get x=20

    (check: original is 20 by 80, Area = 1600
    second is 22 by 85, Area = 1870)
    difference in area = 1870-1600 = 270

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