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The square of Janets age is 400 more then the square of the sum of Kim's and Sue's...

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primrose1e | eNotes Newbie

Posted October 21, 2013 at 7:39 PM via web

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The square of Janets age is 400 more then the square of the sum of Kim's and Sue's ages. Kim's and Sue's ages total 10 less then Janets age. Find the square of the ages of Janet, Kim, and Sue

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baxthum8 | High School Teacher | (Level 3) Associate Educator

Posted October 21, 2013 at 9:49 PM (Answer #1)

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Let Janet's age be "x".

Kim+Sue's ages = x - 10

The square of Janet is `x^2.`

The square of the sum of Kim & Sue's ages = `(x-10)^2`

Since Janet's is 400 more,

`x^2 = (x-10)^2 + 400`

`x^2 = x^2-20x+100+400`

`20x = 500` 

`x = 25`

Janets is 25 years old, and Kim and Sue's ages together total 15.

The square of Kim's age is 625.  The square of the sum of Kim and Sues ages is 225.

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primrose1e | eNotes Newbie

Posted October 24, 2013 at 7:34 PM (Reply #1)

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thank you so much

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