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45 votes
45 votes
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 sq. feet. find the original area of the square

User Andrey Bienkowski
by
2.9k points

2 Answers

25 votes
25 votes

Answer:

The original area of the square was 24

Explanation:

Let's say the dimension of the new square is 9 and 10, that'll make 90

Let's say the original dimensions were 9 - 7, 10 + 2 which is 2, 12

The area of the original dimensions is 24 square feet and they altered that to make the resulting rectangle 90 square feet.

User Amit Kumar Singh
by
3.2k points
12 votes
12 votes

Answer:

The area of the original SQUARE is 64 sq feet. x = 8

It was an 8 × 8 SQUARE.

Explanation:

Let x = the original side length.

x + 7 is a new side

x - 2 is the other new side. Its a rectangle now.

Area of a rectangle:

A = length × width

A = (x+7)(x-2)

90 = x^2 +5x -14

Solve. Subtract 90.

0 = x^2 + 5x - 104

Factor.

0 = (x + 13)(x - 8)

x + 13 = 0 and x-8=0

x = -13 and x = 8

-13 is discarded because lengths cannot be negative.

x = 8 is the original side length of the square.

Area is 8×8 = 64 sqft

User Yanni Wang
by
2.7k points
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