Solve the system of equations using determinants calculator

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  • 3 x 3 Systems Solver

This calculator solves system of three equations with three unknowns (3x3 system). The calculator will use the Gaussian elimination or Cramer's rule to generate a step by step explanation.

examples

Solve by using Gaussian elimination: $$ \begin{aligned} x + 2y - z & = 2 \\[2ex] x - y + 2z & = 5 \\[2ex] 2x + 2y + 2z & = 12 \end{aligned} $$

Solve by using Cramer's rule $$ \begin{aligned} -x + \frac{2}{3}y - 2z & = 2 \\[2ex] 5x + 7y - 5z & = 6 \\[2ex] \frac{1}{4}x + y - \frac{1}{2}z & = 2 \end{aligned} $$

About Cramer's rule

This calculator uses Cramer's rule to solve systems of three equations with three unknowns. The Cramer's rule can be stated as follows:

Given the system:

$$ \begin{aligned} a_1x + b_1y + c_1z = d_1 \\ a_2x + b_2y + c_2z = d_2 \\ a_3x + b_3y + c_3z = d_3 \end{aligned} $$

with

$$ D = \left|\begin{array}{ccc} a_1 & b_1 & c_1 \\ a_2 & b_2 & c_2 \\ a_3 & b_3 & c_3 \\ \end{array}\right| \ne 0 $$ $$ D_x = \left|\begin{array}{ccc} d_1 & b_1 & c_1 \\ d_2 & b_2 & c_2 \\ d_3 & b_3 & c_3 \\ \end{array}\right| $$ $$ D_y = \left|\begin{array}{ccc} a_1 & d_1 & c_1 \\ a_2 & d_2 & c_2 \\ a_3 & d_3 & c_3 \\ \end{array}\right| $$ $$ D_z = \left|\begin{array}{ccc} a_1 & b_1 & d_1 \\ a_2 & b_2 & d_2 \\ a_3 & b_3 & d_3 \\ \end{array}\right| $$

then the solution of this system is:

$$ x = \frac{D_x}{D} $$ $$ y = \frac{D_y}{D} $$ $$ z = \frac{D_z}{D} $$

Example: Solve the system of equations using Cramer's rule

$$ \begin{aligned} 4x + 5y -2z= & -14 \\ 7x - ~y +2z= & 42 \\ 3x + ~y + 4z= & 28 \\ \end{aligned} $$

Solution: First we compute $ D,~ D_x,~ D_y $ and $ D_z $.

$$ \begin{aligned} & D~~ = \left|\begin{array}{ccc} {\color{blue}{4}} & {\color{red}{~5}} & {\color{green}{-2}} \\ {\color{blue}{7}} & {\color{red}{-1}} & {\color{green}{~2}} \\ {\color{blue}{3}} & {\color{red}{~1}} & {\color{green}{~4}} \end{array}\right| = -16 + 30 - 14 - 6 - 8 - 140 = -154\\ & D_x = \left|\begin{array}{ccc} -14 & {\color{red}{~5}} & {\color{green}{-2}} \\ ~42 & {\color{red}{-1}} & {\color{green}{~2}} \\ ~28 & {\color{red}{1}} & {\color{green}{~4}} \end{array}\right| = 56 + 280 - 84 - 56 + 28 - 840 = -616\\ & D_y = \left|\begin{array}{ccc} {\color{blue}{4}} & -14 & {\color{green}{-2}} \\ {\color{blue}{7}} & ~42 & {\color{green}{~2}} \\ {\color{blue}{3}} & ~28 & {\color{green}{~4}} \end{array}\right| = 672 - 84 - 392 + 252 - 224 + 392 = 616\\ & D_Z = \left|\begin{array}{ccc} {\color{blue}{4}} & {\color{red}{~5}} & -14 \\ {\color{blue}{7}} & {\color{red}{-1}} & ~42 \\ {\color{blue}{3}} & {\color{red}{~1}} & ~28 \end{array}\right| = -112 + 630 - 98 - 42 - 168 - 980 = -770\\ \end{aligned} $$

Therefore,

$$ \begin{aligned} & x = \frac{D_x}{D} = \frac{-616}{-154} = 4 \\ & y = \frac{D_y}{D} = \frac{ 616}{-154} = -4 \\ & z = \frac{D_z}{D} = \frac{-770}{-154} = 5 \end{aligned} $$

Note: You can check the solution using above calculator

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This online calculator will help you to solve a system of linear equations using Cramer's rule.

Using this online calculator, you will receive a detailed step-by-step solution to your problem, which will help you understand the algorithm how to solve system of linear equations using Cramer's rule.

Calculator

Guide

Linear equations solver: Solving by Cramer's rule.

The number of equations in the system:

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You can input only integer numbers, decimals or fractions in this online calculator (-2.4, 5/7, ...). More in-depth information read at these rules.



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Method and examples

Method
 

Solving systems of linear equations using
Cramer's Rule method

 
Enter Equations line by line like
2x+5y=16
3x+y=11
Or 2, 5, 16
3, 1, 11
Or (8-18.1906i), (-2+13.2626i), 100
(2-13.2626i), (1+14.7706i), 0

  1. `2x+y+z=5,3x+5y+2z=15,2x+y+4z=8`
  2. `2x+5y=16,3x+y=11`
  3. `2x+5y=21,x+2y=8`
  4. `2x+y=8,x+2y=1`
  5. `2x+3y-z=5,3x+2y+z=10,x-5y+3z=0`
  6. `x+y+z=3,2x-y-z=3,x-y+z=9`
  7. `x+y+z=7,x+2y+2z=13,x+3y+z=13`
  8. `2x-y+3z=1,-3x+4y-5z=0,x+3y-6z=0`

 
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Solve the system of equations using determinants calculator

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Solve the system of equations using determinants calculator
Solve the system of equations using determinants calculator
Solve the system of equations using determinants calculator
Solve the system of equations using determinants calculator
Solve the system of equations using determinants calculator
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How do you solve a system using determinants?

How to solve a system of two equations using Cramer's rule..
Evaluate the determinant D, using the coefficients of the variables..
Evaluate the determinant. ... .
Evaluate the determinant. ... .
Find x and y..
Write the solution as an ordered pair..
Check that the ordered pair is a solution to both original equations..