Two researchers are studying the decline of orangutan populations. In one study, a population of 784 orangutans is expected to decrease at a rate of 25 orangutans per year. In a second study, the population of a group of 817 orangutans is expected to decrease at a rate of 36 per year. After how many years will the two populations be the same?
The two populations will be the same after ___
years.

Question

Two researchers are studying the decline of orangutan populations. In one study, a population of 784 orangutans is expected to decrease at a rate of 25 orangutans per year. In a second study, the population of a group of 817 orangutans is expected to decrease at a rate of 36 per year. After how many years will the two populations be the same?
The two populations will be the same after ___ 
 years.

evoker · Answer

basically you need two linear equation to describe each the one would be y=-25x+784
and the other would be y=-36x+817.  Then to find when they will have the same y we set them equal to each other or -25x+784=-36x+817  rearranging yields11x=33 or after x=3 years they will have the same pop.

ohmyquaffle · Answer

thank you so so much!

welshfella · Answer

equation relating population and years for the first one is 
y = 784 - 25x

can you figure out what the equation for the second lot?

welshfella · Answer

@Evoker  please dont do the  question for the poster. Try to get him involved in the solution. he/ she will learn more that way.

evoker · Answer

I personally believe students should have multiple questions on a topic, as long as explanations are given in detail, at least one fully explained example is useful for students.