The Solution To The System Of Equations Below Is { (-2, -1)$} . . . { \begin{array}{l} 2x - 3y = -1 \\ 11x - 9y = -13 \end{array} \} When The First Equation Is Multiplied By { -3$}$, The Sum Of The Two Equations Is Equivalent

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Introduction

Solving a system of equations is a fundamental concept in mathematics, and it has numerous applications in various fields such as physics, engineering, economics, and computer science. In this article, we will explore the solution to a system of two linear equations in two variables. We will use the method of substitution and elimination to find the solution.

The System of Equations

The system of equations we will be working with is:

2xβˆ’3y=βˆ’111xβˆ’9y=βˆ’13\begin{array}{l} 2x - 3y = -1 \\ 11x - 9y = -13 \end{array}

The Method of Elimination

One of the methods used to solve a system of equations is the method of elimination. This method involves adding or subtracting the equations to eliminate one of the variables. In this case, we will multiply the first equation by -3 to make the coefficients of y's in both equations opposite.

Multiplying the First Equation by -3

When the first equation is multiplied by -3, the sum of the two equations is equivalent. This is because the coefficients of y's in both equations are now opposite.

βˆ’6x+9y=311xβˆ’9y=βˆ’13\begin{array}{l} -6x + 9y = 3 \\ 11x - 9y = -13 \end{array}

Adding the Two Equations

Now, we can add the two equations to eliminate the variable y.

(βˆ’6x+9y)+(11xβˆ’9y)=3+(βˆ’13)5x=βˆ’10\begin{array}{l} (-6x + 9y) + (11x - 9y) = 3 + (-13) \\ 5x = -10 \end{array}

Solving for x

Now that we have eliminated the variable y, we can solve for x.

5x=βˆ’10x=βˆ’10/5x=βˆ’2\begin{array}{l} 5x = -10 \\ x = -10/5 \\ x = -2 \end{array}

Substituting x into One of the Original Equations

Now that we have found the value of x, we can substitute it into one of the original equations to find the value of y.

2xβˆ’3y=βˆ’12(βˆ’2)βˆ’3y=βˆ’1βˆ’4βˆ’3y=βˆ’1βˆ’3y=3y=βˆ’1\begin{array}{l} 2x - 3y = -1 \\ 2(-2) - 3y = -1 \\ -4 - 3y = -1 \\ -3y = 3 \\ y = -1 \end{array}

The Solution to the System of Equations

Therefore, the solution to the system of equations is:

(βˆ’2,βˆ’1)(-2, -1)

Conclusion

In this article, we have explored the solution to a system of two linear equations in two variables. We have used the method of elimination to find the solution. We have also shown how to multiply the first equation by -3 to make the coefficients of y's in both equations opposite. This has allowed us to add the two equations to eliminate the variable y. We have then solved for x and substituted it into one of the original equations to find the value of y. The solution to the system of equations is (-2, -1).

The Importance of Solving Systems of Equations

Solving systems of equations is an essential skill in mathematics and has numerous applications in various fields. It is used to model real-world problems, such as the motion of objects, the flow of fluids, and the behavior of electrical circuits. It is also used in computer science to solve problems in computer graphics, game development, and artificial intelligence.

Real-World Applications of Solving Systems of Equations

Solving systems of equations has numerous real-world applications. Some of these applications include:

  • Physics: Solving systems of equations is used to model the motion of objects, such as the trajectory of a projectile or the motion of a pendulum.
  • Engineering: Solving systems of equations is used to design and optimize systems, such as electrical circuits, mechanical systems, and thermal systems.
  • Economics: Solving systems of equations is used to model economic systems, such as the behavior of supply and demand, and the impact of government policies on the economy.
  • Computer Science: Solving systems of equations is used in computer graphics, game development, and artificial intelligence to solve problems such as 3D rendering, collision detection, and machine learning.

Conclusion

Q: What is a system of equations?

A: A system of equations is a set of two or more equations that are related to each other through the variables in the equations.

Q: What are the different methods used to solve a system of equations?

A: There are several methods used to solve a system of equations, including:

  • Substitution method: This method involves substituting the expression for one variable from one equation into the other equation.
  • Elimination method: This method involves adding or subtracting the equations to eliminate one of the variables.
  • Graphical method: This method involves graphing the equations on a coordinate plane and finding the point of intersection.

Q: What is the difference between a linear equation and a nonlinear equation?

A: A linear equation is an equation in which the highest power of the variable is 1. For example, 2x + 3y = 5 is a linear equation. A nonlinear equation is an equation in which the highest power of the variable is greater than 1. For example, x^2 + 3y = 5 is a nonlinear equation.

Q: Can a system of equations have more than one solution?

A: Yes, a system of equations can have more than one solution. This is known as an inconsistent system. For example, the system of equations:

x + y = 2 x + y = 3

has no solution because the two equations are contradictory.

Q: Can a system of equations have no solution?

A: Yes, a system of equations can have no solution. This is known as an inconsistent system. For example, the system of equations:

x + y = 2 x - y = 2

has no solution because the two equations are contradictory.

Q: Can a system of equations have infinitely many solutions?

A: Yes, a system of equations can have infinitely many solutions. This is known as a dependent system. For example, the system of equations:

x + y = 2 2x + 2y = 4

has infinitely many solutions because the two equations are equivalent.

Q: How do I know which method to use to solve a system of equations?

A: The choice of method depends on the type of system of equations and the variables involved. If the system of equations is linear and has two variables, the substitution or elimination method may be used. If the system of equations is nonlinear or has more than two variables, the graphical method may be used.

Q: What are some common mistakes to avoid when solving systems of equations?

A: Some common mistakes to avoid when solving systems of equations include:

  • Not checking for inconsistent systems: Make sure to check if the system of equations is inconsistent before trying to solve it.
  • Not checking for dependent systems: Make sure to check if the system of equations is dependent before trying to solve it.
  • Not using the correct method: Make sure to use the correct method for the type of system of equations.
  • Not checking for extraneous solutions: Make sure to check for extraneous solutions when solving a system of equations.

Q: How do I check for extraneous solutions?

A: To check for extraneous solutions, substitute the solution back into one of the original equations and check if it is true. If it is not true, then the solution is extraneous.

Q: What are some real-world applications of solving systems of equations?

A: Solving systems of equations has numerous real-world applications, including:

  • Physics: Solving systems of equations is used to model the motion of objects, such as the trajectory of a projectile or the motion of a pendulum.
  • Engineering: Solving systems of equations is used to design and optimize systems, such as electrical circuits, mechanical systems, and thermal systems.
  • Economics: Solving systems of equations is used to model economic systems, such as the behavior of supply and demand, and the impact of government policies on the economy.
  • Computer Science: Solving systems of equations is used in computer graphics, game development, and artificial intelligence to solve problems such as 3D rendering, collision detection, and machine learning.

Conclusion

In conclusion, solving systems of equations is an essential skill in mathematics and has numerous applications in various fields. It is used to model real-world problems, such as the motion of objects, the flow of fluids, and the behavior of electrical circuits. It is also used in computer science to solve problems in computer graphics, game development, and artificial intelligence. By understanding the different methods used to solve systems of equations and avoiding common mistakes, you can become proficient in solving systems of equations and apply it to real-world problems.