Answer
40° and 140°
Work Step by Step
1. Once two angles form straight line, you know they must add up to be $180^{\circ}$. Don't be thrown by the coefficients being negative; it just means that we should expect a negative number of x.
(-4x) + (-14x) = 180
-18x = 180
x = -10
2. Insert the value of x to find the unknown angles
(-4)(-10) = 40°
(-14)(-10) = 140°