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Adah wants to buy a rug for a room that is 19 feet wide and 26 feet long. She wants to leave a uniform strip of floor around the rug. She can afford to buy 330 square feet of carpeting. What dimensions should the rug have?

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User Kjh
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\bold{\huge{\underline{ Solution }}}

Given :-

  • Adah wants to buy a rug for room that is 19 feet wide and 26 feet long.
  • She wants to leave a uniform strip of floor around the rug
  • She can only afford to buy 330 sq. feet carpet.

To Find :-

  • We have to find the dimensions of the rug .

Let's Begin :-

Here, we have

  • The dimensions of Adah room that is 19 feet wide and 26 feet long.

But,

  • She wants to leave a uniform strip of floor around the rug.

Therefore,

Let the width of the uniform strip of the floor be x

So, The new dimensions of the room will be


  • \sf{ (19 - 2x)\: \:and \: \: (26 - 2x)}
  • She can only afford to buy 330 sq.feet

We know that,

Area of rectangle


\bold{\red{ = Length} }{\bold{\red{*{ Breath}}}}

Subsitute the required values,


\sf{ ( 19 - 2x) }{\sf{*{(26 - 2x) = 330}}}


\sf{19(26 - 2x) }{\sf{*{ - 2x (26 - 2x) = 330}}}


\sf{ 494 - 38x - 52x + 4x^(2) = 330 }


\sf{ 494 - 38x - 52x + 4x^(2) = 330 }


\sf{ - 90x + 4x^(2) = 330 - 494 }


\sf{ - 90x + 4x^(2) = - 164 }

  • Arrange the given terms in general quadratic equation that ax² + bx + c = 0


\sf{ 4x^(2) - 90x + 164 = 0 }


\sf{ 4x^(2) - 82x - 8x + 164 = 0 }


\sf{ 2x( 2x - 41 ) -4( 2x - 41 ) = 0 }


\sf{ (2x - 4) ( 2x - 41) = 0}


\sf{ x = 2 , x = }{(41)/(2)}

  • We can only take only 1 value that is x = 2 because 41/2 will give negative result and dimensions of rectangle can never be negative.

Therefore,

Length of the rug


\sf{ (19 - 2x) = 19 - 2(2)}


\sf{ = 19 - 4}


\sf{ = 15\: feet}

Breath of the rug


\sf{ (26 - 2x) = 19 - 2(2)}


\sf{ = 26 - 4}


\sf{ = 22\:feet}

Hence, The dimensions of the rug are 15 feet and 22 feet.

User Jitendra A
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