The steps
Use the same order each time so when an answer is wrong, you know which step to re-check. Variables shows the whole topic in one place.
Why one line at a time
One algebraic move per line. If you combine two moves on one line and get stuck, you cannot see which move was wrong.
Worked pattern
Example: balance an equation—add or subtract on both sides, or multiply or divide both sides by the same nonzero number. Write the new equation on the next line each time.
Two ways to write work
One step per line Two steps on one line
Confirm
Core lesson
Go deeper: Variables. Use the calculators below with your own loan or bill numbers, not only the examples on this page.