MathCalcLab

System of Equations

Solve 2×2 systems of linear equations with Cramer's rule, step by step

System of Linear Equations (2×2)

\(a_1x + b_1y = c_1\)
\(a_2x + b_2y = c_2\)

First Equation

Second Equation

Results

Enter values and click Calculate to see the result.

System of Linear Equations

A system of two linear equations can be solved using Cramer's rule, which uses determinants.

Key Concepts:

  • If D ≠ 0: Unique solution (lines intersect at one point)
  • If D = 0 and ratios equal: Infinite solutions (same line)
  • If D = 0 and ratios differ: No solution (parallel lines)
  • The determinant represents the "area" of the coefficient matrix
\(\begin{cases} a_1x + b_1y = c_1 \\ a_2x + b_2y = c_2 \end{cases}\)

Worked Examples

Cramer's Rule

\(x = \frac{D_x}{D}, y = \frac{D_y}{D}, \quad D \neq 0\)

Example: 2x + 3y = 8, x − y = 1

\(D = -5, x = 2.2, y = 1.2\)

Parallel Lines

\(x+y=1, \quad x+y=2\): No solution

Coincident Lines

\(x+y=1, \quad 2x+2y=2\): Infinitely many solutions
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