Answer:

Step-by-step explanation:
You plug in the points in this equation 
So
= 
Step-by-step explanation:
To find the perimeter of something, we add all of the measurements of the sides together.
A rectangle has 4 sides, this means we must double the algebraic hints given to us.
If we add them all up together it will look like this:
x-9+x-9+3x-4+3x-4=138
If we simplify it by collecting the like terms:
8x-26=138
We add 26 onto 138
8x=164
To find out what x equals, we divide by 8:
164÷8= 20.5
Answer:
x=20.5cm
x-9 is 11.5
3x-4 is 57.5
I know that you will not give 100 points but just wanted to help.
Answer:
a) 13 m/s
b) (15 + h) m/s
c) 15 m/s
Step-by-step explanation:
if the location is
y=x²+3*x
then the average velocity from 3 to 7 is
Δy/Δx=[y(7)-y(3)]/(7-3)=[7²+3*7- (3²+3*3)]/4= 13 m/s
then the average velocity from x=6 to to x=6+h
Δy/Δx=[y(6+h)-y(6)]/(6+h-6)=[(6+h)²+3*(6+h)- (6²+3*6)]/h= (2*6*h+3*h+h²)/h=2*6+3= (15 + h) m/s
the instantaneous velocity can be found taking the limit of Δy/Δx when h→0. Then
when h→0 , limit Δy/Δx= (15 + h) m/s = 15 m/s
then v= 15 m/s
also can be found taking the derivative of y in x=6
v=dy/dx=2*x+3
for x=6
v=dy/dx=2*6+3 = 12+3=15 m/s