SOLUTION: A baby's crib has an area of 1,131 square inches and a perimeter of 136 inches. What are the dimensions of the crib?

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Question 892432: A baby's crib has an area of 1,131 square inches and a perimeter of 136 inches. What are the dimensions of the crib?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
A=1131
p=136
Let dimensions be x and y.

LIST WHAT YOU KNOW INCLUDING INFORMATION FROM THE DESCRIPTION
p=2x+2y;
A=xy.

Solve for x and y. A quadratic equation will occur. Do everything in variables until x and y are solved, AS FORMULAS, ALL IN VARIABLES.

Substitute the values for A and p and evaluate x and y.


-----The less general way-------
2x+2y=136 and xy=1131.
Perimeter simplifies to x%2By=68 from which y=68-x.
-
xy=1131
x%2868-x%29=1131
68x-x%5E2=1131
68x-x%5E2-1131=0
x%5E2-68x%2B1131=0
x=%2868%2B-+sqrt%2868%5E2-4%2A1131%29%29%2F2
x=%2868%2B-+sqrt%28100%29%29%2F2
x=%2868%2B-+10%29%2F2
x=29 or x=39

Checking for corresponding y values, you'll find in respective order, 39 and 29.
ANSWER: Dimensions are 29 and 39.