Answer: 
Step-by-step explanation:
For this exercise you can use the following formula for calculate the slope:

In this case you know that the given line passes through the points (-3,0) and (1.4). Therefore you can identify that:

Then, in order to calculate the slope of this line, you must substitute the coordinates of the points into the formula:

Finally, evaluating, you get that the slope of this line is the following:

<h2>
Answer:</h2>
<h3>
<em>x=45degrees</em></h3>
<h2>
Step-by-step explanation:</h2>
Let the angle to be solved be x
Let the supplement/compliment by y
x+y=90 Complimentary angles add up to 90 degrees.
x+3y=180 Supplementary angles add up to 180 degrees, the other angle is thrice the other compliment.
Evaluating this as a system:
x+y=90 Isolate x:
x=90−y Input into the other equation:
(90−y)+3y=180 Combine like terms, isolate y and its coefficients:
2y=90 Isolate y
y=45 Input into the first equation:
x+45=90 Isolate x:
x=45degrees
2x/7 = 12/14
Multiply both sides of the equation by 7:
2x = 84/14
Simplify:
2x = 6
Divide both sides by 2 and your answer is....
x = 3
adjacent, and complementary