SOLUTION: Lorna wants to enclose a rectangular area next to the river. She only has 400 ft. of
fence and she wants to enclose an area of 1500 ft2
, set the rectangular area
dimensions
Question 1074413: Lorna wants to enclose a rectangular area next to the river. She only has 400 ft. of
fence and she wants to enclose an area of 1500 ft2
, set the rectangular area
dimensions Found 2 solutions by josgarithmetic, ikleyn:Answer by josgarithmetic(39617) (Show Source):
You can put this solution on YOUR website! If x is one dimension and y is the other, and if y is the side opposite the river bank, then:
Let x be the dimension along the river and y that perpendicular to the river.
Then
x + 2y = 400, (1)
xy = 1500. (2)
From (1), x = 400 - 2y. Substitute it into (2). You will get
(400-2y)*y = 1500.
2y^2 -400y + 1500 = 0,
y^2 - 200y + 750 = 0,
= = = .
There are 2 solutions: 1) y = 196.18 ft; then x = 400 - 2*196.18 = 15.29 ft.
2) y = 3.82 ft; then x = 400 - 2*3.82 = 392.36 ft.
Check. 1) 196.18*7.64 = 1499 ft^2 (close !); 2) 3.82*392.36 = 1500 ft^2.
Answer. 1) x = 15.29 ft, y = 196.18; 2) x = 392.36, y = 3.82 ft.
(