Question

(d) problem 20: (first taught in lesson 42)
find y.
after you enter your answer press go.
y =

Explanation:

Step1: Identify vertical - angles

Vertical angles are equal. The angle $3y$ and the angle $(84 - y)$ are vertical angles. So, $3y=84 - y$.

Step2: Solve the equation for y

Add $y$ to both sides of the equation: $3y + y=84 - y+y$, which simplifies to $4y = 84$.

Step3: Isolate y

Divide both sides of the equation $4y = 84$ by 4: $y=\frac{84}{4}=21$.

Answer:

$y = 21$