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HW HELP?!?!?!?!?!? and please explain how you got it step by step?

2 sides of an equilateral triangle measure (y+10) units and ( y to the second power - 2) units.

If the perimeter of the triangle is 21 units, what is the value of y?

1 Answer

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  • ?
    Lv 7
    8 years ago
    Favorite Answer

    perimeter of EQUILATERAL triangle is 21 units

    Each side is 21/3 = 7

    Therefor

    y + 10 = 7

    Subtract 10 from both sides

    y = -3

    Check other side to confirm

    y^2 - 2 = 7

    Add 2 to both sides

    y^2 = 9

    Take square root of both sides

    y = ±3

    Disregard extraneous root 3

    y = -3

    m09282013

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