Ok so if -6 is the y intercept you look for -6 on the y axis and use rise over run up one over one until you can't plot anymore and then down one over one and do the same thing did that help you Phil?
The answer to the above question can be explained as under -
We know that, the sum of angles of triangle is 180°.
So, vertex angle plus base angles are equal are equal to 180°.
Let the vertex angle be represented by "v" and base angles be represented by "b".
Thus, v + b + b = 180°
So, v + 2b = 180°
Next, the question says, the vertex angle is 20° less than the sum of base angles.
Thus, 2b - 20° = v
<u>Thus, we can conclude that the correct option is A) v + 2b = 180°, 2b - 20° = v</u>
<h2>Long short story: I tried ;-; </h2>