Y = mx + b
m is your slope AKA rate of change
b is the y intercept.
from the graph we can see that the y intercept (b) is 15. (look at the y axis and see what point the line crosses on the y, here it is 15, in-between 10 and 20)
slope is rate of change. to figure this out remember slope = rise over run:

so pick two points. how much does one point rise after the other point you picked? In the graph it rises 1 square so rise = 1
Now looking at the same two points, how far away from each other are they on the x axis? Looking at the graph they are 2 squares away from each other. so run = 2
Now plug these numbers into the rise over run formula:

Now we have everything we need to put into our formula for a line:


For number 16 you should get:

after you do the same steps again yourself
The GCF is based upon what integer divides evenly into two numbers; the LCM is based upon what integer two numbers share in a list of multiples. The GCF must be a prime number; the LCM must be a composite number.
Show another picture i cant see you
We need 6.5% to a decimal so..
6.5% /100 = 0.065
$21.30 X 0.065 = 1.3845 tax on the shirt
So.. we add the price of the shirt, and the amount of tax on the shirt
$21.30 + 1.3845 = $22.6845
Answer = $22.68