/*! 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 61 Finding the Value of a Constant ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Finding the Value of a Constant In Exercises 61 and \(62,\) find the value of \(k\) such that the system of linear equations is inconsistent. $$ \left\\{\begin{aligned} 4 x-8 y &=-3 \\ 2 x+k y &=16 \end{aligned}\right. $$

Short Answer

Expert verified
The value of k that makes the system of equations become inconsistent is \( k = -4 \).

Step by step solution

01

Convert both equations into slope-intercept form \( y = mx + b \)

The first equation is: \( 4x - 8y = -3 \). Divide each term of the equation by -8 to isolate \( y \), and we obtain \( y = 0.5x + 0.375 \). \n\n The second equation is: \( 2x + ky = 16 \). To isolate \( y \), we get \( y = -2/kx + 16/k \).
02

Compare the slopes of two lines

To effect inconsistency (parallel lines), the slopes of two lines must be equal. So we get: \n\n \( 0.5 = -2/k \)
03

Solve the single variable algebraic equation

The equation would be in the form: \( k = -2 / 0.5 \). Solving this equation will give us the value of \( k \).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

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

Slope-Intercept Form
Understanding the slope-intercept form is fundamental when you're dealing with linear equations. It is expressed as \( y = mx + b \), where \( m \) represents the slope of the line and \( b \) signifies the y-intercept, which is the point where the line crosses the y-axis. To convert a linear equation into this form, you need to isolate \( y \) on one side of the equation.

Take for example the given system of equations. By manipulating the first equation \( 4x - 8y = -3 \), we can divide all terms by -8 to reconfigure it into slope-intercept form, yielding \( y = 0.5x + 0.375 \). This method is particularly useful as it immediately shows the rate at which \( y \) changes with \( x \), which is the slope, and where the line will intersect the y-axis. For the second equation \( 2x + ky = 16 \), dividing by \( k \) and then rearranging gives us a slope of \( -2/k \), which is important for identifying the type of system we're dealing with.
Parallel Lines
Lines are parallel when they have the same slope, meaning they will never intersect no matter how far they extend in both directions. This concept is crucial when solving for an inconsistent system, which is a set of equations representing parallel lines, thus having no solution.

In the case of our equations, after converting to slope-intercept form, you'll notice that both lines must have the same slope \( m \) to be parallel. From the given equations, the slope of the first line is \( 0.5 \), and we manipulated the second equation to express its slope as \( -2/k \). Setting these two slopes equal to each other because parallel lines have equal slopes allows us to solve for the value of \( k \) that would make the system inconsistent—that is, make the lines parallel.
Single Variable Algebraic Equation
The single variable algebraic equation is a foundational element of algebra that involves numbers and variables. It's often written in the form of \( ax + b = 0 \), where \( a \) and \( b \) are constants. To solve for the unknown variable \( x \), you would execute operations to isolate \( x \) on one side of the equation.

In the context of finding an inconsistent system, we already established that our slopes must match (from the parallel lines concept), leading us to the equation \( 0.5 = -2/k \). This is a simple single-variable equation where \( k \) is the variable. To isolate \( k \), we multiply both sides by \( k \) and then divide both sides by 0.5 to find that \( k \) must equal \( -4 \). Therefore, when \( k = -4 \), the two equations form an inconsistent system since they would represent parallel lines.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Break-Even Analysis In Exercises 57 and 58 , find the sales necessary to break even \((R=C)\) for the total cost \(C\) of producing \(x\) units and the revenue \(R\) obtained by selling \(x\) units. (Round to the nearest whole unit.) $$C=8650 x+250,000, \quad R=9950 x$$

Acid Mixture Thirty liters of a 40\(\%\) acid solution is obtained by mixing a 25\(\%\) solution with a 50\(\%\) solution. (a) Write a system of equations in which one equation represents the amount of final mixture required and the other represents the percent of acid in the final mixture. Let \(x\) and \(y\) represent the amounts of the 25\(\%\) and 50\(\%\) solutions, respectively. (b) Use a graphing utility to graph the two equations in part (a) in the same viewing window. As the amount of the 25\(\%\) solution increases, how does the amount of the 50\(\%\) solution change? (c) How much of each solution is required to obtain the specified concentration of the final mixture?

Finding Systems of Linear Equations In Exercises \(79 - 82 ,\) find two systems of linear equations that have the ordered triple as a solution. (There are many correct answers.) $$ ( 3 , - 4,2 ) $$

Data Analysis: Wildlife A wildlife management team studied the reproductive rates of deer in three tracts of a wildlife preserve. Each tract contained 5 acres. In each tract, the number of females \(x ,\) and the percent of females \(y\) that had offspring the following year were recorded. The table shows the results.$$ \begin{array} { | c | c | c | c | } \hline \text { Number, } x & { 100 } & { 120 } & { 140 } \\ \hline \text { Percent, y } & { 75 } & { 68 } & { 55 } \\\ \hline \end{array} $$ (a) Use the data to create a system of linear equations. Then find the least squares regression parabola for the data by solving the system. (b) Use a graphing utility to graph the parabola and the data in the same viewing window. (c) Use the model to estimate the percent of females that had offspring when there were 170 females. (d) Use the model to estimate the number of females when 40\(\%\) of the females had offspring.

Finding the Equation of a Circle In Exercises \(55 - 58\) , find the equation of the circle $$x ^ { 2 } + y ^ { 2 } + D x + E y + F = 0$$ that passes through the points. To verify your result, use a graphing utility to plot the points and graph the circle. $$ ( 0,0 ) , ( 0 , - 2 ) , ( 3,0 ) $$

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.