Solve two-step linear equations of the form px + q = r, including negative and fractional coefficients, using inverse operations.
A two-step equation takes exactly two moves to solve: first undo any addition or subtraction, then undo any multiplication or division. Always undo in that order -- addition/subtraction first, multiplication/division second -- even when the numbers are negative or fractions.
Every move must be done to BOTH sides of the equation, keeping the balance true. Checking your answer by substituting it back into the ORIGINAL equation takes ten seconds and catches nearly every mistake.
Mastery looks like: They solve a two-step equation with any combination of signs, including fractional coefficients, and check the result.
Common stumbles: Undoing the operations in the wrong order; performing a move on only one side of the equation.
See it visually
Interactive, spoken-aloud tools that show this idea in motion.