2×2 Systems of Equations Solver

Solve a₁x + b₁y = c₁; a₂x + b₂y = c₂. Cramer's rule via determinants.

Inputs

Result

Solution
x = 3.500000, y = 2.000000
D = -14.0000.
  • a₁x + b₁y = c₁2x + 3y = 13
  • a₂x + b₂y = c₂4x + -1y = 12
  • D (det)-14.0000
  • Dx-49.0000
  • Dy-28.0000
  • x = Dx / D3.50000000
  • y = Dy / D2.00000000
  • Verify eq 113.0000
  • Verify eq 212.0000

Step-by-step

  1. D = a₁b₂ − a₂b₁ = -14.0000.
  2. Dx = c₁b₂ − c₂b₁ = -49.0000.
  3. Dy = a₁c₂ − a₂c₁ = -28.0000.
  4. x = Dx/D = 3.500000; y = Dy/D = 2.000000.

How to use this calculator

  • Enter coefficients of both equations.
  • Read x and y.

About this calculator

Cramer's rule for 2×2 systems: x = Dx/D, y = Dy/D where D = a₁b₂ − a₂b₁ is the coefficient determinant. When D = 0, the lines are parallel (no solution) or identical (infinite solutions). For larger systems (3×3, 4×4) Cramer's rule still works but Gaussian elimination is faster. 2×2 is the bread-and-butter case in physics (mixture problems), economics (supply/demand), and elementary algebra.

Frequently asked

When the two equation lines are parallel (different y-intercepts: no solution) or identical (same line: infinite solutions).

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