The dimensions of a square are altered so that one dimension is increased by 7 feet and the other is decreased by 2 feet. The area of the resulting rectangle is 90 square feet. Find the original area of the square

Respuesta :

I got 64 square feet.

My work is shown in the image.

For possible questions:

1: you can find x+7 and x-2 because the sides of the square can be measured as x, and x+7 means 7 more than the original; x-2 means 2 less than the original.

2: solved via factoring. Not sure if you've learned it or not.

3: reject the negative numbers because you can't have negative sides in a square.

Ver imagen WatermelonRockCandy

Area of rectangle is multiplication of length and width.

Original area of square will be 64 square feet.

Let us consider the each side of square is x feet.

Since, one dimension is increased by 7 feet and the other is decreased by 2 feet . then, it become a rectangle have length (x + 7) and width (x - 2) feet.

Area of resulting rectangle = (x + 7)(x - 2)

                  [tex](x + 7)(x - 2)=90\\\\x^{2} +5x-104=0\\\\x^{2} +13x-8x-104=0\\\\x(x+13)-8(x+13)=0\\\\(x-8)(x+13)=0\\\\x=8,x=-13[/tex]

Since, length can not be negative. So  x = 8 feet

Original are of square =  [tex]x^{2} =8^{2}[/tex]

                                     = 64 square feet

Learn more:

https://brainly.com/question/23148123