A linear equation has variables only to the first power — no x², no √x. The graph is a straight line.
Drag the sliders
y = a·x + b - c
How to solve ax + b = c
- Move the constant: subtract b from both sides.
- Divide both sides by a.
- Whatever you do to one side, do to the other — that keeps the equation balanced.
- The solution is the x where the line ax + b − c crosses zero (the marked root).
Your turn
Solve 3x + 4 = 19.
Recap
- Linear means variables to the first power only — graph is a straight line.
- Isolate x by undoing operations in reverse order.
- Check by substituting your answer back in.
Standard form
Try it
5x − 7 = 18
Add 7: 5x = 25. Divide by 5: x = 5.