Answer:
a. {(0, 7), (-1, 6)}
Step-by-step explanation:

subtract the equations

for
, substitute x = 0

for
, substitute x = 0

The slope-intercept form:

The formula of a slope:

We have the points (-4, 47) and (2, -16). Substitute:

Therefore we have:

Put the coordinates of the point (2, -16) to the equation:

Answer: 
A + B + C = 180
<span>C = 180 - A - B </span>