First we calculate how many ways you can choose four books from a set of eight.
We use the formula n! / [r! * (n-r)!]
8! / [4! * 4!]
= 8*7*6*5 / 4*3*2*1 = 70 ways
Then we have to calculate how many permutations can be made from 4 objects which equals 4*3*2*1 = 24
So, the TOTAL number of ways = 70 * 24 = 1,680
If we are eliminating x, we would multiply the 2nd equation by -5
5x + 18y = 23
x + 3y = 2....multiply by -5
-----------------
5x + 18y = 23
-5x - 15y = - 10 (result of multiplying by -5)
----------------add
0 + 3y = 13.....bye-bye x :)
Alright, we know that the slope intercept form is y=mx+b, where x and y remain variables, m stands for the slope and b stands for the y intercept.
Because you should already have the slope from the first part (because slope is the same thing as rate of change), you should know that the slope is 60. The y-intercept should be your y value when x=0, and if you set up the equation in terms of years since Elliot has started his business, the year 2000 should be equal to x=0, so the y intercept should be equal to 750.
Now that you know the slope intercept form and what each part of it means, you can plug in what you have to get the final equation, which should be y=60x+750
Answer:
a) y = 9x
b) For every increase of 1 hour the price to rent the lane increases by $9.
c) $27
Step-by-step explanation:
a) Since it costs $18 for 2 hours we can infer that for every 1 hour it costs $9.
So, the equation would look like this:
y = 9x
b) In this context, for every increase of 1 hour the price to rent the lane increases by $9. Like the question gave us, the price for 2 hours cost $18.
c) Plug 3 into the equation:
y = 9(3)
y = 27
Therefore, it costs $27 to rent the lane for 3 hours.
<em>I hope this helps!!</em>
<em>- Kay :)</em>
