SOLUTION: A rectangular lot whose perimeter is 420 feet is fenced along three sides. An expensive fencing along the lot's lenght costs $17 per foot, and an inexpensive fencing along the two

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Question 743347: A rectangular lot whose perimeter is 420 feet is fenced along three sides. An expensive fencing along the lot's lenght costs $17 per foot, and an inexpensive fencing along the two side widths costs only $8 per foot. The total cost of the fencing along the three sides comes to $3470. What are the lot's dimensions?
Solve the problem above.
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Length and width assigning not really important except to be consistant with how assigned and used.

Taking either dimension as L for "length" and then W for width,
The whole rectangle is as 2%28L%2BW%29=420.

You could then choose fencing costs of 17*L and 2*8W, so this combined cost for those THREE sides would be 17L%2B16W=3470.

The system based on that is:
2%28L%2BW%29=420 and 17L%2B16W=3470.

Solving the perimeter equation for W and substituting into the cost equation gives (try doing this on your own) highlight%28L=110%29 feet.
Using this in the formula used for W gives highlight%28W=100%29 feet.