The value of r so the line that passes through (-5,2) and (3,r) has a slope of -1/2 is -2
<u>Solution:</u>
Given that line is passing through point (-5, 2) and (3, r)
Slope of the line is 
Need to determine value of r.
Slope of a line passing through point
is given by following formula:
--- eqn 1

On substituting the given value in (1) we get

Hence the value of "r" is -2
This problem can be solve by graphing (technology), as suggested.
The answer is posted as an attached image. We see that after about 14.75 years, the invading species will surpass the indigenous population.
If it needs to be solved mathematically and accurately, the math is a little more advanced, using the bisection method, or Newton's method.
However, we can also do that by trial and error, starting from 14.75. It is easier than you might think.
Post if you would like to have more information on one or the other methods.
Note: the scale of y has been shrunk by 1000, so each unit on the y-axis represents 1000 frogs.
You must calculate how many ways can 2 people be selected from 65.
The formula is:
n! / r! * (n-r)! =
65! / 2! * 63! =
65*64*63! / 2 * 63! =
65*64 / 2 =
2,080 handshakes
Source:
http://www.1728.org/combinat.htm
Answer:
1. 1,000
2. 395
Step-by-step explanation:
Hope it helps lol