Example: Solving a System of Three Equations Using Cramer's Rule
Solve the system of equations using Cramer's rule: \left\{\begin{array}{l} 3x - 5y + 4z = 5 \\ 5x + 2y + z = 0 \\ 2x + 3y - 2z = 3 \end{array} ight.. First, evaluate the main determinant using the coefficients of the variables. By expanding by minors, we find . Next, evaluate by using the constants to replace the coefficients of ; expanding by minors yields . Then, evaluate by replacing the coefficients of with the constants, yielding . Finally, evaluate by replacing the coefficients of with the constants, which yields . Find the values of , , and by substituting into the formulas: , , and . Write the solution as the ordered triple and check that it is a solution to all three original equations.
0
1
Tags
OpenStax
Intermediate Algebra @ OpenStax
Ch.4 Systems of Linear Equations - Intermediate Algebra @ OpenStax
Algebra
Related
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
An analyst is using Cramer's Rule to solve a system of three linear equations. Match each algebraic component used in the process to its correct functional description.
An inventory manager at a logistics company is determining the exact number of three different types of shipping containers (, , and ) to load onto a cargo plane based on weight, volume, and budget constraints. They have modeled these constraints as a system of three linear equations and will solve it using Cramer's Rule. Arrange the procedural steps the manager must follow to find the solution in the correct chronological order.
A project manager at a construction firm is using Cramer's Rule to solve a system of three linear equations to allocate budget across three different departments (, , and ). If represents the determinant of the coefficient matrix and represents the determinant calculated by replacing the -column with the constants, which formula correctly identifies the budget for department ?
Auditing a Cramer's Rule Calculation
A resource manager is using Cramer's Rule to solve a system of three linear equations that determines the allocation of labor across three project phases, , , and . To calculate the determinant , the manager must replace the column containing the -coefficients in the main coefficient matrix with the constant terms from the equations.