The measures of 13 of the 14 angles of a 14-gon add up to 2042. What must the fourteenth angle measure to?

156 degrees

Step-by-step explanation:

The interior angles of a convex n-gon add to (n -2)180°, so a 14-gon has a sum of angles of 12×180° = 2160°. Since 13 angles sum to 2004°, the remaining one must be ...

... 2160° -2004° = 156°

It must have the same slope as the given line, so

m = -A/B = -1/-2 = 1/2

So far, we have

y = mx + b = x/2 + b

Use the given point to find b.

4 = -2/2 + b = -1 + b

b = 5

y = x/2 + 5

Multiply through by 2.

2y = x + 10

Standard form:

x - 2y = -10