Vertical angles are equal
7x - 19 = 4x + 2
7x - 4x = 2 + 19
3x = 21
x = 21/3
x = 7
m∠ABC = 4x + 2 = 4*7 + 2 = 28 + 2 = 30°
U do the formula
slope = -9/4
The slope-intercept form:

m - slope
b - y-intercept → (0, b).
We have the points (4, 7) and (0, 7) → b = 7.
Calculate the slope:

Therefore we have 
The standard form: 
<h3>Answer: y = 7.</h3><h3><em>It's a horizontal line.</em></h3>
78
step by step explanation:
first: divide 600 and 15
answer to 600/15: 40
second: divide 3120 and 40
final answer: 78