Answer:
A
Step-by-step explanation:
0 is sea lvl so just add and subsubtract
Answer:
21 times
Step-by-step explanation:
Given


Required
The least number of times to land on 3
This is calculated using:



Answer:
The equation of the line is: 
Step-by-step explanation:
Equation of a line:
The equation of a line has the following format:

In which m is the slope and b is the y-intercept.
Two points:
We have these following two points in this exercise:
x = -6, y = -3, so (-6,-3)
x = 4, y = 3, so (4,3)
Finding the slope:
Given two points, the slope is given by the change in y divided by the change in x.
Change in y: 3 - (-3) = 3 + 3 = 6
Change in x: 4 - (-6) = 4 + 6 = 10
So

Then

Finding b:
We replace one of the points in the equation to find b. I will use (4,3).




The equation of the line is: 
You should add -77 to 77 because it will cancel out.
We know the perimeter is the total sum of all sides of the shape, we can use this to form an equation: the perimeter=1st side + 2nd side + 3rd side + 4th side 39a-7=9a+(5a+1)+(17a-6)+4th side.
Collect like terms to get 39a-7=31a-5+4th side
If we move everything but the 4th side over to the left we can solve
C. 8a-2=4th side is the correct answer