<em><u>Solution:</u></em>
<em><u>The decreasing function is given as:</u></em>
Where,
y is future value
a is initial value
r is decreasing rate in decimal
t is time period
From given,
a = 25000
number of years = x
future value = P
Therefore,
Thus the function is found
y = -9
Ok so to write the equation of the line you will need the slope and y-intercept. Since we are given two-point we can easily find the slope by using this equation for slope formula:
So now that we have our equation we can just plug in the numbers:
After subtracting you should get:
0/8
Since zero is in the numerator and you can't divide zero by anything, the slope is 0. We still need the y-intercept for the equation however since the slope is 0 there is no need to put anything else.
Then to find the y-intercept all you have to do is plug in one of the coordinatines into the slope equation to solve, for example, using the point (5,-9):
B is the variable for the y-intercept. Also notice how I put 0 as our slope into the equation. Now all you have to do is solve for b. Which you would get b = -9. Since you have your slope and your y-intercept now you just write out your equatoin for the line which is:
y = 0x - 9
**Just write it as
y = -9