Simplify Calculator
Distributes any parentheses first, then combines like terms — the two moves 'simplify' actually means. The result is checked against the original expression before it is shown.
How it works
How the Simplify Calculator works
the part a result on its own leaves out
What simplifying actually does
Simplifying is two separate moves, always in the same order: distribute any parentheses first, multiplying everything inside by whatever sits outside, then combine like terms — add up the coefficients of matching powers of x. Doing these out of order, or skipping the first one, is where most simplification errors come from.
Why this calculator sticks to polynomials in x
Distributing and combining like terms is a specific, well-defined pair of moves for sums, differences and products of powers of x. A function like sin or sqrt, or x sitting in a denominator, needs a different kind of simplifying — this calculator declines those rather than guessing at a result.
Common mistakes
Common mistakes with simplifying expressions
the errors that actually show up, not every possible slip
Distributing to only the first term inside the parentheses
3(2x + 1) is 6x + 3, not 6x + 1 — the 3 multiplies every term inside, not just the first one.
Combining terms with different powers of x
3x and 3x² are not like terms and cannot be added into 6x or 6x². Only matching powers of x combine — x with x, x² with x², and so on.
Losing a sign when distributing a negative
-2(3x - 1) is -6x + 2, not -6x - 2 — the negative sign flips the sign of every term it is distributed across, including a term that was already negative.
Questions
Asked often enough to answer here
answers that change how you work
What does it mean to simplify an expression?
Distribute any parentheses, then combine like terms — add the coefficients of matching powers of x. 3(2x + 1) - 4x distributes to 6x + 3 - 4x, then combines to 2x + 3.
What are like terms?
Terms with the exact same power of x. 3x and 5x are like terms and combine to 8x; 3x and 3x² are not, and stay separate.
Why does it decline some expressions?
It handles polynomials in x — sums, products and constant divisions of powers of x. A function like sin(x), or x in a denominator, needs different rules, so the calculator says so rather than guessing at an answer.
How do I check a simplification myself?
Substitute the same number for x in both the original and the simplified expression — the two results should match exactly. This calculator runs that check internally before showing a result.
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