Nouplo

Matrix calculator

Every step shown, in exact fractions.

Output
Enter a matrix: one row per line, entries separated by spaces or commas — e.g. 2 1 on the first line and 1 3 on the second. Fractions such as 3/4 are fine.

Your files stay on your device

This tool runs entirely in your browser. What you paste is processed on your device and is never sent to a server, so it is safe to use with tokens, keys and unpublished text.

Example

Example: a ticket problem solved as a 3 × 3 system, step by step

A school play sold 120 tickets for $1,180: adults pay $12, children $7, seniors $9, and twice as many children as seniors came. With x1 adults, x2 children and x3 seniors: x1 + x2 + x3 = 120, 12x1 + 7x2 + 9x3 = 1180, x2 − 2x3 = 0.

  1. Choose Solve a linear system and type the augmented matrix, constants last: 1 1 1 120 / 12 7 9 1180 / 0 1 -2 0.
  2. Step 1, R2 ← R2 − 12·R1, gives 0 −5 −3 | −260; step 2 divides that row by −5: 0 1 3/5 | 52.
  3. Three more steps clear the columns, with exact fractions such as −13/5 on the way, until only the identity is left.
Unknown Value
x1, adults 60
x2, children 40
x3, seniors 20

Unique solution, in five row operations: 60 adults, 40 children and 20 seniors. The determinant of the coefficients is 13, not 0, which is why there is exactly one answer.

How it works

  1. Type matrix A with one row per line and the entries separated by spaces or commas — fractions like 1/3 and decimals are fine.
  2. Choose the operation; for A × B or A + B, type matrix B in its own box. To solve a system, put the constants in the last column.
  3. Read the result and every row operation that led to it, in exact fractions with decimals beside them.

Frequently asked questions

How do I solve a system of equations?
Write it as an augmented matrix: one row per equation, the coefficients then the constant. 2x + y − z = 8, −3x − y + 2z = −11, −2x + y + 2z = −3 is “2 1 -1 8 / -3 -1 2 -11 / -2 1 2 -3”, and gives x1 = 2, x2 = 3, x3 = −1. It also tells you when there is no solution or infinitely many, with the free variables.
Why fractions?
The calculation is exact: 1/3 stays 1/3 instead of 0.333…, so no rounding creeps into an inverse or a determinant. Decimals are shown beside any fraction. The inverse of “2 1 / 1 3” is [3/5 −1/5; −1/5 2/5].
How is the determinant worked out?
By row reduction to a triangle: each step is shown, a row swap flips the sign, and the determinant is the product of the diagonal. For “2 1 / 1 3” it is 5.
Which formats can I paste?
Rows on separate lines, [[1,2],[3,4]], or 1 2; 3 4 on one line. Up to 10 × 10.
What if the matrix has no inverse?
Then its determinant is 0 and the calculator says so: “1 2 3 / 2 4 6 / 1 1 1” is singular, because its second row is twice the first. In a system the same thing shows up as no solution or infinitely many.
Why are the unknowns called x1, x2, x3?
A system can have up to ten of them, so the calculator numbers the columns instead of naming them x, y, z: x1 is the first column, x2 the second. A free variable is written t1, t2 and so on.
Is anything saved?
No. It is calculated in your browser.

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