Question

x = ___
y = ___

Explanation:

Step1: Find the value of x

The sum of the angles 120° and 4x° is 180° (linear - pair of angles). So, 120 + 4x=180.
Subtract 120 from both sides: 4x = 180 - 120.
4x = 60.
Divide both sides by 4: $x=\frac{60}{4}=15$.

Step2: Find the value of y

Assume the two horizontal lines are parallel. Then the angle (3y - 15)° and the 120° angle are corresponding angles (if the lines are parallel), and they are equal. So, 3y-15 = 120.
Add 15 to both sides: 3y=120 + 15.
3y = 135.
Divide both sides by 3: $y=\frac{135}{3}=45$.

Answer:

x = 15
y = 45