/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 79 In Problems 79-86, solve each sy... [FREE SOLUTION] | 91Ó°ÊÓ

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In Problems 79-86, solve each system of equations using any method you wish. \(\left\\{\begin{array}{l}2 x+3 y=11 \\ 5 x+7 y=24\end{array}\right.\)

Short Answer

Expert verified
x = -5, y = 7

Step by step solution

01

- Choose a Method

To solve the system of equations, we can use either the substitution method or the elimination method. For this example, the elimination method will be used.
02

- Align the Equations

Write the system of equations in a standard form: 1. 2x + 3y = 11 2. 5x + 7y = 24
03

- Eliminate One Variable

Multiply the equations by suitable constants to make the coefficients of one of the variables (x or y) the same in both equations. Multiply the first equation by 5 and the second by 2: 1. 5(2x + 3y) = 5(11) 2. 2(5x + 7y) = 2(24) This gives: 1. 10x + 15y = 55 2. 10x + 14y = 48
04

- Subtract the Equations

Subtract the second equation from the first to eliminate the variable x: (10x + 15y) - (10x + 14y) = 55 - 48 This simplifies to: y = 7
05

- Substitute Back to Find the Other Variable

Substitute y = 7 back into one of the original equations. Use the first equation for convenience: 2x + 3(7) = 11 Simplify and solve for x: 2x + 21 = 11 2x = 11 - 21 2x = -10 x = -5
06

- Write the Solution

The solution to the system of equations is x = -5 and y = 7. Write it as an ordered pair: (-5, 7)

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

elimination method
The elimination method is a popular technique for solving systems of linear equations. This method involves manipulating the given equations in a way that allows one of the variables to be canceled out or eliminated, making it easier to solve for the remaining variable. Here’s a summary of the steps involved:
- Multiply each equation by appropriate constants to equalize the coefficients of one of the variables.
- Add or subtract the equations to eliminate one of the variables.
- Solve the resulting single-variable equation.
- Substitute the found value back into one of the original equations to solve for the other variable.
Using the elimination method can be very efficient, especially when dealing with a system of equations where it is straightforward to make the coefficients of one variable identical.
substitution method
The substitution method is another effective way to solve systems of linear equations. This method involves solving one of the equations for one variable in terms of the other variable, and then substituting this expression into the second equation. The steps can be summarized as follows:
- Solve one of the equations for one variable.
- Substitute the expression obtained into the other equation to get an equation in one variable.
- Solve this equation.
- Substitute the found value back into the expression obtained in step 1 to find the value of the other variable.
The substitution method can be particularly useful when one of the equations is already solved for one variable or can be easily manipulated into that form.
linear equations
Linear equations are algebraic expressions that represent straight lines when graphed. Each term in a linear equation typically involves a constant or a product of a constant and a single-variable exponent, like x or y, raised to the power of one. In our example, we have two linear equations:
\[2x + 3y = 11\right.\right\]
\[5x + 7y = 24\right.\right\]
The goal when solving such a system of linear equations is to find the values of the variables that make both equations true simultaneously. Linear equations can be solved using various methods including substitution, elimination, and graphical methods. Understanding how to handle linear equations is foundational for solving more complex algebraic problems.
variable elimination
Variable elimination is a key part of the elimination method. This technique involves removing one variable to simplify the process of solving the system of equations. In our example, by manipulating the coefficients of the x-variable, we were able to eliminate x and solve for y. Here’s a brief rundown:

- Multiply the first equation by a constant so that the coefficients of x in both equations become the same.
- Multiply the second equation by another constant if necessary.
- Subtract one equation from the other, effectively eliminating the x-variable.
- Solve the resulting equation for y.
- Once y is found, substitute its value back into one of the original equations to find x.
This method is invaluable in algebra because it reduces a complex problem to a simpler one, making it easier to reach the solution.
ordered pairs
Ordered pairs are used to represent the solution of a system of equations graphically on the coordinate plane. An ordered pair is written in the form (x, y), where x and y correspond to values that satisfy both equations in the system. In our solved system:
- The ordered pair (-5, 7) is the solution.
This means that substituting x = -5 and y = 7 into both given equations will make the statements true. Ordered pairs provide a convenient way to represent solutions and make it easy to plot them on a graph for visual verification.

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Most popular questions from this chapter

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