Question

problem 18: (first taught in lesson 18) find y. after you enter your answer press go. y =

Explanation:

Step1: Identify vertical - angle relationship

Vertical angles are equal. Here, $y$ and $3y + 10$ are vertical angles, so $y=3y + 10$ is incorrect. They are supplementary to the same right - angle. The sum of the two angles $y+(3y + 10)=90$ (since they are complementary to the right - angle formed by the intersecting lines).

Step2: Simplify the equation

$y+3y + 10=90$ can be combined like terms. We get $4y+10 = 90$.

Step3: Solve for $y$

Subtract 10 from both sides: $4y=90 - 10$, so $4y=80$. Then divide both sides by 4: $y=\frac{80}{4}=20$.

Answer:

$y = 20$