/*! 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 101 Because variables appear in deno... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Because variables appear in denominators, the system $$\begin{aligned}&\frac{5}{x}+\frac{15}{y}=16\\\&\frac{5}{x}+\frac{4}{y}=5\end{aligned}$$ is not a linear system. However, we can solve it in a manner similar to the method for solving a linear system by using a substitution-of-variable technique. Let \(t=\frac{1}{x}\) and let \(u=\frac{1}{y} \). Repeat Exercise 100 for the second equation in the given system.

Short Answer

Expert verified
x = 5, y = 1.

Step by step solution

01

Substitute Variables

First, substitute the given expressions for \(x\) and \(y\) using the changes of variables: \(t = \frac{1}{x}\) and \(u = \frac{1}{y}\). This implies that \(x = \frac{1}{t}\) and \(y = \frac{1}{u}\). Rewrite the system using these substitutions.
02

Rewrite First Equation

Substitute \(t\) and \(u\) into the first equation: \[\frac{5}{x} + \frac{15}{y} = 16\] becomes \[5t + 15u = 16\].
03

Rewrite Second Equation

Substitute \(t\) and \(u\) into the second equation: \[\frac{5}{x} + \frac{4}{y} = 5\] becomes \[5t + 4u = 5\].
04

Set Up the Linear System

Now, we have a linear system of equations: \[\begin{aligned} 5t + 15u &= 16 \ 5t + 4u &= 5 \end{aligned}\]
05

Eliminate Variable t

Subtract the second equation from the first to eliminate \(t\): \[(5t + 15u) - (5t + 4u) = 16 - 5\] which simplifies to \[11u = 11\].
06

Solve for u

Divide both sides of the equation \(11u = 11\) by 11 to find \(u\): \[u = 1\].
07

Substitute Back to Find t

Substitute \(u = 1\) into one of the equations, e.g., \(5t + 4u = 5\): \[5t + 4 \times 1 = 5\] simplifies to \[5t + 4 = 5\].
08

Solve for t

Subtract 4 from both sides: \[5t = 1\]. Divide by 5 to solve for \(t\): \[t = \frac{1}{5}\].
09

Find x and y

Recall \(t = \frac{1}{x}\) and \(u = \frac{1}{y}\). Substitute back to find \(x\) and \(y\): \[x = \frac{1}{t} = 5, \quad y = \frac{1}{u} = 1\].

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.

Substitution Technique
The substitution technique is a powerful method for solving equations and systems of equations. It involves replacing variables with equivalent expressions to simplify the system. In this problem, dealing with equations that initially appear non-linear due to variables in denominators, substitution helps us turn them into linear ones.
By introducing new variables, such as letting \( t = \frac{1}{x} \) and \( u = \frac{1}{y} \), we reframe our problem. This clever substitution transforms the fractions into simple coefficients of linear equations. This method not only eases the computation but also provides a structured way to tackle complex algebraic problems.
Implementing the substitution technique allows us to solve for the newly defined variables first and then revert back to solve for the original ones, ensuring accuracy and simplicity in finding solutions.
Non-Linear Systems
Non-linear systems are those which involve equations that are not simply straight lines when graphed. They can include quadratics, exponentials, or, as in our exercise, rational expressions. The presence of variables in the denominator makes the system initially non-linear, complicating straightforward algebraic solutions.
The given system seems intricate because of its rational form, but by substituting the variables and transforming the system, we temporarily bypass its non-linearity. Calculating solutions for non-linear systems often requires different mathematical strategies like graphing, substitution, or elimination, each tailored to the specific type of non-linearity encountered.
  • Non-linear systems can represent complex real-world problems such as population dynamics or financial models.
  • Solution approaches may involve numerical or analytical techniques, depending on the complexity.
Linear System Solving
Linear system solving involves finding the values of variables that satisfy a set of linear equations. These systems are characterized by equations that outline straight lines when graphed in the coordinate plane. In this exercise, we convert our original non-linear system into a linear one using substitution.
Once it's transformed, the goal is to solve the linear system by common methods such as substitution, elimination, or using matrices. Linear systems are foundational in mathematics for their predictable structure and solution methods.
For the equations in the form:
  • \(5t + 15u = 16\)
  • \(5t + 4u = 5\)
The solution involves eliminating one variable to easily find the values of the other, reflecting familiar procedures in algebra classes. It provides a step-by-step approach to finding clear, concise answers.
Variable Elimination
Variable elimination is one of the key methods to solve systems of linear equations. It focuses on removing one variable to simplify solving for others. In our transformed system, after substitution, we have two equations. To eliminate, we subtracted one equation from the other, removing a variable in the process.
In the equation \[(5t + 15u) - (5t + 4u) = 16 - 5\],
we eliminate \(t\), simplifying to \[11u = 11\]. This straightforward subtraction highlights the efficiency of variable elimination. Completing this step allows us to solve for one variable directly, simplifying the path to solving for the remaining unknowns.
  • Efficiency: reduces the complexity of systems by directly solving for one variable.
  • Commonly used in conjunction with substitution for optimal results.
Variable elimination is beneficial in linear algebra and higher mathematics, providing a systematic approach to solving diverse equation systems.

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

Draw a sketch of the two graphs described with the indicated number of points of intersection. (There may be more than one way to do this.) A circle and a parabola; four points.

Use the shading capabilities of your graphing calculator to graph each inequality or system of inequalities. $$3 x+2 y \geq 6$$

To analyze population dynamics of the northern spotted owl, mathematical ecologists divided the female owl population into three categories: juvenile (up to 1 year old), subadult (1 to 2 years old), and adult (over 2 years old). They concluded that the change in the makeup of the northern spotted owl population in successive years could be described by the following matrix equation. $$\left[\begin{array}{c} j_{n+1} \\ s_{n+1} \\ a_{n+1} \end{array}\right]=\left[\begin{array}{rrr} 0 & 0 & 0.33 \\ 0.18 & 0 & 0 \\ 0 & 0.71 & 0.94 \end{array}\right]\left[\begin{array}{c} j_{n} \\ s_{n} \\ a_{n} \end{array}\right]$$ The numbers in the column matrices give the numbers of females in the three age groups after \(n\) years and \(n+1\) years. Multiplying the matrices yields the following. $$\begin{aligned} &j_{n+1}=0.33 a_{n}\\\ &s_{n+1}=0.18 j_{n}\\\ &a_{n+1}=0.71 s_{n}+0.94 a_{n} \end{aligned}$$ (Source: Lamberson, R. H., R. McKelvey, B. R. Noon, and C. Voss, "A Dynamic Analysis of Northern Spotted Owl Viability in a Fragmented Forest Landscape," Conservation Biology, Vol. \(6, \text { No. } 4 .)\) (a) Suppose there are currently 3000 female northern spotted owls: 690 juveniles, 210 subadults, and 2100 adults. Use the preceding matrix equation to determine the total number of female owls for each of the next 5 years. (b) Using advanced techniques from linear algebra, we can show that, in the long run, $$ \left[\begin{array}{c} j_{n+1} \\ s_{n+1} \\ a_{n+1} \end{array}\right]=0.98359\left[\begin{array}{c} j_{n} \\ s_{n} \\ a_{n} \end{array}\right] $$ What can we conclude about the long-term fate of the northern spotted owl? (c) In this model, the main impediment to the survival of the northern spotted owl is the number 0.18 in the second row of the \(3 \times 3\) matrix. This number is low for two reasons: The first year of life is precarious for most animals living in the wild, and juvenile owls must eventually leave the nest and establish their own territory. If much of the forest near their original home has been cleared, then they are vulnerable to predators while searching for a new home. Suppose that, due to better forest management, the number 0.18 can be increased to \(0.3 .\) Rework part (a) under this new assumption.

Solve each nonlinear system of equations analytically. $$\begin{aligned}&x^{2}+y^{2}=5\\\&x-y=1\end{aligned}$$

Solve each system graphically. Check your solutions. Do not use a calculator. $$\begin{aligned}&x-y=3\\\&x^{2}+y^{2}=9\end{aligned}$$

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.