Answer:
![y\in (-\infty ,5]](https://tex.z-dn.net/?f=y%5Cin%20%28-%5Cinfty%20%2C5%5D)
Step-by-step explanation:
In this problem, we need to write "Twenty times y is at most 100 in interval notation
".
20 times y means, 20y
Atmost means an inequality which is 
ATQ,

i.e.

We can also write it as :
![y\in (-\infty ,5]](https://tex.z-dn.net/?f=y%5Cin%20%28-%5Cinfty%20%2C5%5D)
Hence, the required interval notation is
.
Answer:
18
Step-by-step explanation:
180-160 = 20 which equals the exterior angle
the sum of exterior angles is 360 so 360/20 = the number of sides as there is an exterior angle for every side
360/20 = 18
Answer:
2.5
Step-by-step explanation:
This is going to be an long answer, so I'm putting the answer first. y=3x-7
First, you have to find the equation of the line given. You can use point slope form for that. You can see that the slope is -1/3, and it goes through (2,2). So, the equation would be
y-2=-1/3(x-2)
Which simplifies to
y=-1/3x+8/3
Now, we can get on to finding the actual answer. The slope of a line perpendicular would be the negative reciprocal of the original slope. That just means you flip it and multiply it by -1. So, the slope of the new line is 3. Now you can use point slope form again and make an equation, which is
y+1=3(x-2)
Which simplifies to
y=3x-7
Please don't ask me why the slope is the negative reciprocal, or how they came up with the formula for the point slope form. I DON'T KNOW. If you want to know so bad you would give up chick-fil-A for the rest of your life, there's always google.