Solving a System of Three Linear Equations Using Cramer's Rule
To solve a system of three linear equations with three variables using Cramer's rule, the procedure is similar to solving a system of two equations, but requires evaluating determinants. Follow these seven steps:
- Evaluate the main determinant , using the coefficients of the variables.
- Evaluate the determinant by using the system's constants in place of the coefficients.
- Evaluate the determinant by using the system's constants in place of the coefficients.
- Evaluate the determinant by using the system's constants in place of the coefficients.
- Find the values of , , and using the formulas , , and .
- Write the final solution as an ordered triple .
- Check that the ordered triple is a valid solution by substituting it back into all three original equations.
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Ch.4 Systems of Linear Equations - Intermediate Algebra @ OpenStax
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Example: Solving a System of Three Equations Using Cramer's Rule
Identifying Dependent and Inconsistent Systems Using Determinants
Solving a System of Three Linear Equations Using Cramer's Rule
Practice: Solving a System of Three Equations Using Cramer's Rule
A project coordinator is solving for three resource allocations (, , and ) using Cramer's Rule. Given the system of equations in standard form: , , and , match each determinant used in the rule to the correct description of its construction.
A logistics coordinator is using Cramer's Rule to solve a system of three linear equations to find the costs of fuel (), labor (), and maintenance (). To find the value of the labor cost (), she must first calculate the determinant . How is constructed from the main coefficient determinant ?
An industrial engineer is using Cramer's Rule to solve for three variables (production time , setup time , and inspection time ) in a manufacturing system. Arrange the following steps in the correct order to solve for the value of setup time ().
A logistics coordinator is using Cramer's Rule to solve a system of three linear equations to determine three unknown shipping costs (, , and ). According to the rule, once the determinants are calculated, the value of the cost is found using the formula , where is the main coefficient determinant and is the determinant specific to the variable .
A data analyst is modeling a quarterly budget using a system of three linear equations with variables , , and . When setting up Cramer's Rule to solve the system, the analyst forms the main determinant by using only the ____ of the variables.
Learn After
As an inventory analyst, you are documenting an automated spreadsheet tool that calculates the individual unit costs of three different raw materials based on recent bulk invoices. The tool uses Cramer's Rule to solve the resulting system of three linear equations. To ensure your team understands the underlying computational logic, arrange the procedural steps of Cramer's Rule in the exact order the tool must execute them.
A resource analyst for a logistics firm is using Cramer's Rule to solve a system of three linear equations to determine the optimal number of shipments (), trucks (), and drivers () needed for a new project. To ensure the analyst remembers the correct procedure, match each component of the rule with its correct definition or formula.
A small business owner is using Cramer's Rule to solve a system of three linear equations to determine the profitability of three different services: consulting (), maintenance (), and repairs (). When calculating the determinant for this system, which set of values must the owner replace with the system's constants?
An inventory manager uses Cramer's Rule to determine the unit costs of three different supplies, represented by the variables , , and . After solving the system and finding the ordered triple , the manager only needs to substitute these values back into one of the original three equations to verify that the solution is correct.
Applying Cramer's Rule Formulas