Replace $y$ in the second equation $x + 2y = 14$ with the expression from the first equation, $y = \tfrac12 x + 3$.

After you substitute, simplify carefully: distribute the $2$, combine like terms, and solve for $x$. Then plug that $x$ back into $y = \tfrac12 x + 3$ to get $y$.

Remember the question asks for $y$, not $x$, so be sure to do the final substitution to find $y$ after you get $x$.

In Desmos, type the first equation as y = 0.5x + 3 and the second equation as x + 2y = 14. Desmos will automatically graph both lines.

Look for the point where the two lines intersect. Tap or click on the intersection point; Desmos will display its coordinates $(x, y)$.

From the displayed intersection coordinates, note the y-coordinate. That y-value is the answer to the question.

The first equation already solves for $y$ as $y = \tfrac12 x + 3$. This makes the substitution method the fastest: plug this expression for $y$ into the second equation.

Take the second equation $x + 2y = 14$ and replace $y$ with $\tfrac12 x + 3$:

Now simplify the left side by distributing the $2$:

Distribute and combine like terms:

So the equation becomes:

Subtract $6$ from both sides:

Divide both sides by $2$ to find $x$.

You should now have $x = 4$. Plug this into $y = \tfrac12 x + 3$:

So, the value of $y$ is 5.