I teach how to solve simple linear equations where the unknown x only appears once, and can be solved by either adding the same number to both sides of the equation, or subtracting the same number from both sides of the equation. (The numbers may be negative.)
So essentially, these are one-step equations, except sometimes we need to simplify something, or switch the sides, before actually solving the equation.
We also deal with the situation of negative x, or −x, being left alone on one side of the equation.
Math Mammoth Grade 7 curriculum (pre-algebra)