Given The System Of Equations Below, Write The System In $A \cdot X = B$ Form.$-3x + 2y = 7$ $5x - 4y = -21$\begin{bmatrix} -3 & 2 \\ 5 & -4 \end{bmatrix} \cdot \begin{bmatrix} X \\ Y \end{bmatrix} = \begin{bmatrix} 7

by ADMIN 220 views

Introduction

In mathematics, systems of equations are a fundamental concept that can be used to solve for multiple variables. One way to represent a system of equations is in matrix form, where the coefficients of the variables are represented as a matrix, and the variables themselves are represented as a column vector. In this article, we will explore how to write a system of equations in the form Aâ‹…X=BA \cdot X = B, where AA is the coefficient matrix, XX is the column vector of variables, and BB is the column vector of constants.

The System of Equations

The system of equations we will be working with is:

−3x+2y=7-3x + 2y = 7

5x−4y=−215x - 4y = -21

To write this system in matrix form, we need to identify the coefficients of the variables and the constants. The coefficients of the variables are the numbers in front of the variables, and the constants are the numbers on the right-hand side of the equations.

Writing the System in Matrix Form

To write the system in matrix form, we will create a coefficient matrix AA, a column vector of variables XX, and a column vector of constants BB. The coefficient matrix AA will have the coefficients of the variables as its elements, and the column vector of variables XX will have the variables themselves as its elements. The column vector of constants BB will have the constants on the right-hand side of the equations as its elements.

The coefficient matrix AA is:

[−325−4]\begin{bmatrix} -3 & 2 \\ 5 & -4 \end{bmatrix}

The column vector of variables XX is:

[xy]\begin{bmatrix} x \\ y \end{bmatrix}

The column vector of constants BB is:

[7−21]\begin{bmatrix} 7 \\ -21 \end{bmatrix}

Writing the System in Aâ‹…X=BA \cdot X = B Form

Now that we have identified the coefficient matrix AA, the column vector of variables XX, and the column vector of constants BB, we can write the system of equations in the form Aâ‹…X=BA \cdot X = B. This is done by multiplying the coefficient matrix AA by the column vector of variables XX to get the column vector of constants BB.

The system of equations in Aâ‹…X=BA \cdot X = B form is:

[−325−4]⋅[xy]=[7−21]\begin{bmatrix} -3 & 2 \\ 5 & -4 \end{bmatrix} \cdot \begin{bmatrix} x \\ y \end{bmatrix} = \begin{bmatrix} 7 \\ -21 \end{bmatrix}

Conclusion

In this article, we have explored how to write a system of equations in the form Aâ‹…X=BA \cdot X = B, where AA is the coefficient matrix, XX is the column vector of variables, and BB is the column vector of constants. We have used the system of equations:

−3x+2y=7-3x + 2y = 7

5x−4y=−215x - 4y = -21

to demonstrate how to write the system in matrix form and then in Aâ‹…X=BA \cdot X = B form. This form is useful for solving systems of equations using matrix operations.

Applications of Matrix Form

The matrix form of a system of equations has many applications in mathematics and other fields. Some of these applications include:

  • Solving Systems of Equations: The matrix form of a system of equations can be used to solve for the variables using matrix operations.
  • Linear Transformations: The matrix form of a system of equations can be used to represent linear transformations, which are used in many areas of mathematics and science.
  • Computer Graphics: The matrix form of a system of equations is used in computer graphics to represent transformations and projections.
  • Physics and Engineering: The matrix form of a system of equations is used in physics and engineering to represent systems of equations and to solve for variables.

Example Use Case

Suppose we have a system of equations that represents the motion of an object in two dimensions. The system of equations is:

x′=2x+3yx' = 2x + 3y

y′=4x−2yy' = 4x - 2y

We can write this system in matrix form as:

[234−2]⋅[xy]=[x′y′]\begin{bmatrix} 2 & 3 \\ 4 & -2 \end{bmatrix} \cdot \begin{bmatrix} x \\ y \end{bmatrix} = \begin{bmatrix} x' \\ y' \end{bmatrix}

We can then use matrix operations to solve for the variables xx and yy.

Conclusion

Q: What is the matrix form of a system of equations?

A: The matrix form of a system of equations is a way of representing a system of equations using matrices. It consists of a coefficient matrix, a column vector of variables, and a column vector of constants.

Q: How do I write a system of equations in matrix form?

A: To write a system of equations in matrix form, you need to identify the coefficients of the variables and the constants. The coefficients of the variables are the numbers in front of the variables, and the constants are the numbers on the right-hand side of the equations. You can then create a coefficient matrix, a column vector of variables, and a column vector of constants.

Q: What is the coefficient matrix in matrix form?

A: The coefficient matrix is a matrix that contains the coefficients of the variables. It is usually denoted by the letter A.

Q: What is the column vector of variables in matrix form?

A: The column vector of variables is a column vector that contains the variables themselves. It is usually denoted by the letter X.

Q: What is the column vector of constants in matrix form?

A: The column vector of constants is a column vector that contains the constants on the right-hand side of the equations. It is usually denoted by the letter B.

Q: How do I write a system of equations in the form A * X = B?

A: To write a system of equations in the form A * X = B, you need to multiply the coefficient matrix A by the column vector of variables X to get the column vector of constants B.

Q: What are the applications of matrix form?

A: The matrix form of a system of equations has many applications in mathematics and other fields. Some of these applications include solving systems of equations, linear transformations, computer graphics, and physics and engineering.

Q: How do I use matrix form to solve systems of equations?

A: To use matrix form to solve systems of equations, you need to multiply the coefficient matrix A by the column vector of variables X to get the column vector of constants B. You can then use matrix operations to solve for the variables.

Q: What are some common mistakes to avoid when writing systems of equations in matrix form?

A: Some common mistakes to avoid when writing systems of equations in matrix form include:

  • Not identifying the coefficients of the variables and the constants correctly.
  • Not creating the coefficient matrix, column vector of variables, and column vector of constants correctly.
  • Not multiplying the coefficient matrix A by the column vector of variables X correctly.

Q: How do I determine if a system of equations can be written in matrix form?

A: A system of equations can be written in matrix form if it has the following properties:

  • The system has two or more equations.
  • The system has two or more variables.
  • The coefficients of the variables are constants.

Q: What are some real-world applications of matrix form?

A: Some real-world applications of matrix form include:

  • Computer graphics: Matrix form is used to represent transformations and projections in computer graphics.
  • Physics and engineering: Matrix form is used to represent systems of equations and to solve for variables in physics and engineering.
  • Linear transformations: Matrix form is used to represent linear transformations, which are used in many areas of mathematics and science.

Conclusion

In conclusion, the matrix form of a system of equations is a powerful tool for solving systems of equations and representing linear transformations. It has many applications in mathematics and other fields, and is used in computer graphics, physics, and engineering. By understanding how to write a system of equations in matrix form, we can solve for variables using matrix operations and represent complex systems of equations in a concise and elegant way.