Reverse the operation
Addition is undone by subtraction. Multiplication is undone by division. Work in reverse order around x.
Free algebra tool
Keep both sides balanced.
Solve a linear equation in the form ax + b = c. You’ll get the answer, every legal move, and a substitution check.
Enter your equation
ax + b = c
Examples: 2x + 5 = 17, −3x + 4 = 19, or 0.5x − 2 = 8.
Your balanced solution will appear here.
Try the example already in the boxes.
Build the pattern
Now solve one without watching.
A new equation appears each time. Enter x, check it, and use the hint only when you need it.
The balance method
Three ideas do most of the work.
Do it to both sides
An equation is a claim of equality. The claim stays true only when both sides receive the same operation.
Substitute your answer
Replace x in the original equation. If both sides evaluate to the same number, your answer is verified.