SOLUTION: It is estimated that at the present rate of deforestation in El Salvador, in 20 years only 53% of the present forest will remain. How long will it take to remove 95% of the forest?

Algebra ->  Algebra  -> Customizable Word Problem Solvers  -> Age -> SOLUTION: It is estimated that at the present rate of deforestation in El Salvador, in 20 years only 53% of the present forest will remain. How long will it take to remove 95% of the forest?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com
Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help!
Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations!

   

Question 107575: It is estimated that at the present rate of deforestation in El Salvador, in 20 years only 53% of the present forest will remain. How long will it take to remove 95% of the forest?
Answer by josmiceli(9697) About Me  (Show Source):
You can put this solution on YOUR website!
I'm assuming this is a linear relation with a negative slope.
I want the vertical axis to be p = percent of present forest
remaining
The horizontal axis is years from the present
The points given are
P1 = (20,.53)
P2 = (x,.05) note that 95% removed leaves 5% left
Also I have the p-intercept (0,1) where 0 represents the present
The equation is p+=+mx+%2B+1 note that when x=0, p = 1
The slope is %28p%5B2%5D+-+p%5B1%5D%29+%2F+%28x%5B2%5D+-+x%5B1%5D%29
+m+=+%28.53+-+1%29+%2F%2820+-+0%29
m+=+-.47+%2F+20
m+=+-.0235
p+=+-.0235x+%2B+1
The question is, when p = .05, what is x?
.05+=+-.0235x+%2B+1
-.0235x+=+-.95
x+=+40.43years answerThis is about 40 y 5 m 5 d