x + my =d

So ... what is the question?

It is probably: what is y?

y = (d-x)/m

The equation you've written is a simple linear equation in two variables, "x" and "y." To solve for "x" or "y," we want to isolate one variable on one side of the equation.

To solve for "x":
1. Start by bringing "my" to the other side of the equation by subtracting it from both sides:
x = d - my

To solve for "y":
1. Start by bringing "x" to the other side of the equation by subtracting it from both sides:
my = d - x
2. Divide both sides of the equation by "m":
y = (d - x) / m

So, depending on which variable you want to solve for, you can use either of these equations.