Question 1028726: How can I solve this?
Year- 1988- 582 trees ,1989- 620 trees, 1990- 658 trees, 1992-734 trees, 1995-848 trees, 1997- 924 trees
Assuming no trees die, what is the total number of trees in the year 2020?
The city claims it can have 5,000 trees in the city by 2088. Is this possible?
What formula did you use to prove it?
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! your data is as follows:
year trees difference difference per year
1988 582
1989 620 38 38
1990 658 38 38
1992 734 76 38
1995 848 114 38
1997 924 76 38
your growth is 38 years per year.
that's a straight line growth.
it fits a straight line equation.
the general form of that equation is y = mx + b
m is the slope
b is the y-intercept.
y is equal to the number of trees.
x is equal to the year from 1988.
1988 means x = 0
1989 means x = 1
etc.
your slope is the change in y divided by the change in x.
when the year changes by 1, the number of trees increased by 38.
your slo0pe is 38.
your equation becomes y = 38x + b
you can take any coordinate of (x,y) to find b.
just replace y with the number of trees and x with the year from 1988.
for example.
in 1988, the number of trees is 582.
x = 0 when the year is 1988.
y = 582 when x = 0
your coordinate point is (0,582)
in the equation of y = 38x + b, replace y with 582 and x with 0 to get 582 = 0 + b.
this results in b = 582.
your equation is y = 3x + 582.
as a test, use the year 1997.
when the year is 1997, x is equal to 1997 - 1988 = 9
when x = 9, y = 38*9 + 582 = 924
this agrees with what your are given, so the formula looks good.
when the year is 2020, x is equal to 2020 - 1988 = 32.
the number of trees is equal to y which is equal to 32*38 + 582 = 1798
when the year is 2088, x is equal to 2088 - 1988 = 100.
the number of trees is equal to y which is equal to 100*38 + 582 = 4382.
the city will not have 5000 trees by 2088 at the growth rate of 38 trees per year.
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