After distributing, you'll have an equation like $5x - 10 = 3y + 10$. What operation can you do to both sides to eliminate the $-10$?

Once you have an equation of the form $5x = \text{(expression in y)}$, what should you do to both sides to solve for $x$?

In Desmos, define a value for $y$, such as y = 2 (any positive value works).

Enter the equation 5(x - 2) = 3y + 10 and solve it for $x$ using the chosen $y$ value. You can do this by rewriting it as 5(x - 2) = 3*2 + 10 (or your chosen value) and solving that simple equation for $x$ by hand or using Desmos's numeric tools, noting the resulting $x$-value.

In Desmos, enter each option’s expression for $x$ using the same $y$ value, for example: xA = (3y + 20)/5, xB = (3y + 10)/5, etc. Compare each computed $x$ to the $x$ you found from the original equation; the correct choice is the one whose expression gives the same $x$-value.

Start with the equation:

Distribute the 5 across the parentheses:

To isolate the $x$ term, get rid of the $-10$ on the left by adding 10 to both sides:

This simplifies to:

Now divide both sides of the equation by 5 to get $x$ alone:

This matches choice A, so the correct equation expressing $x$ in terms of $y$ is $x = \dfrac{3y + 20}{5}$.