a. 
b. For every month the pine tree grows about 0.67 inches.
c. <em> </em>It represents the height of the tree at the moment Ariel started to record the heights.
<h2>
Explanation:</h2>
<h3>PART A.</h3>
In this exercise we have that in July Ariel recorded the height of a pine tree and how quickly it was expected to grow in next several months. From the Table, we can get the following points:

It is obvious that this problem follows a linear equation, so our goal is to find the equation that matches the Table.
The point slope form of the equation of a line is:

Finding (m):

Finally, the equation of the line is:

<h3>
PART B.</h3>
In this case, we have that:
- The x-axis represents the <em>Number of Months </em>the pine tree was expected to grow.
- The y-axis represents the <em>Height of the Tree </em>in inches.
Since the slope o a line is:

Then, this means that<em> every three months the pine tree grows two inches, </em><em>or </em><em>for every month the pine tree grows about 0.67 inches.</em>
<h3>PART C.</h3>
The y-intercept can be found setting
. So, from our equation:

So the y-intercept is
and<em> represents the height of the tree at the moment Ariel started to record the heights.</em>
<h2>Learn more:</h2>
Slope Intercept form: brainly.com/question/4192440
#LearnWithBrainly
Answer:
77.
Proved
78.
Proved
79.
Proved.
80.
Proved.
Step-by-step explanation:
77. Left hand side
=
=
=
{Since we know,
}
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= Right hand side (Proved)
78. Left hand side
=
=
{Since
}
=
= Right hand side (Proved)
79. Left hand side
=
=
{Since
}
=
= Right hand side
80. Left hand side
=
=
{Since
}
=
=
= Right hand side. (Proved)
<span>let the angles be x and y.
as they are compliment
x+y=90
also given
x=7y
substituting value of x in first equation
7y+y=90
8y=90
therefore
y=11.25
x=7*y=78.75</span>