(1) Since I don't know the dimensions of the rectangle, I will assume it is a square. Given the area = 4850, then the sides are the square root of 4850, which = 69.64. Since the perimeter of a square is simply 4s, s = length of a side, then YES your 280 ft of fencing can do the job.
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(2) This one requires you to set up the given equation and then substitute the values of t, where
year t
1987 0
1988 1
1989 2
1990 3
etc.
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The equation is
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Using Excel, I created the following table for the years 1987-2007. Notice that the sales go up for a while and then start back down.
yr t Sales
1987 0 0.500
1988 1 1.265
1989 2 1.960
1990 3 2.585
1991 4 3.140
1992 5 3.625
1993 6 4.040
1994 7 4.385
1995 8 4.660
1996 9 4.865
1997 10 5.000
1998 11 5.065
1999 12 5.060
2000 13 4.985
2001 14 4.840
2002 15 4.625
2003 16 4.340
2004 17 3.985
2005 18 3.560
2006 19 3.065
2007 20 2.500