/*! 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 44 Solve the following system for \... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Solve the following system for \(x\) and \(y\) in terms of \(a\) and \(b\) where \(a \neq b:\) $$\left\\{\begin{array}{l}a x+b y=1 / a \\\b^{2} x+a^{2} y=1\end{array}\right.$$

Short Answer

Expert verified
\(x = \frac{a^3 - a^2b - b^4}{a^2(a^3 - b^3)}, \quad y = \frac{a^3 - b^2}{a^3 - b^3}\)

Step by step solution

01

Write the System of Equations

First, write down the given system of equations: \[ ax + by = \frac{1}{a} \] \[ b^2x + a^2y = 1 \].
02

Express One Variable in Terms of the Other

Solve the first equation for \(x\): \[ ax + by = \frac{1}{a} \] \[ ax = \frac{1}{a} - by \] \[ x = \frac{1}{a^2} - \frac{by}{a} \].
03

Substitute to the Second Equation

Substitute \(x\) from the first equation into the second equation: \[ b^2\left(\frac{1}{a^2} - \frac{by}{a}\right) + a^2y = 1 \].
04

Simplify the Second Equation

Expand and simplify the equation: \[ \frac{b^2}{a^2} - \frac{b^3y}{a} + a^2y = 1 \].
05

Solve for y

Rearrange the terms to find \(y\): \[ a^2y - \frac{b^3y}{a} = 1 - \frac{b^2}{a^2} \] \[ y(a^3 - b^3) = a^3 - b^2 \] \[ y = \frac{a^3 - b^2}{a^3 - b^3} \].
06

Solve for x

Substitute \(y\) back to the expression for \(x\) found in Step 2: \[ x = \frac{1}{a^2} - \frac{b}{a} \left(\frac{a^3 - b^2}{a^3 - b^3}\right) \] \[ x = \frac{1}{a^2} - \frac{b(a^3 - b^2)}{a(a^3 - b^3)} \] \[ x = \frac{a^3 - a^2b - b^4}{a^2(a^3 - b^3)} \].
07

Simplify the Expressions of x and y

Ensure that both \(x\) and \(y\) are in their simplest forms: \[ y = \frac{a^3 - b^2}{a^3 - b^3} \] and \[ x = \frac{a^3 - a^2b - b^4}{a^2(a^3 - b^3)} \].

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.

Linear Equations
Linear equations are the building blocks of algebra. An equation is termed "linear" when it graphs as a straight line in a two-dimensional space, commonly described by the equation format: \( ax + by = c \). In our given system of equations, each equation is linear because each term is either a constant or the product of a constant and a single variable.
These equations are powerful tools because they allow us to predict one variable based on another. For example, the first equation, \( ax + by = \frac{1}{a} \), lets us express either \( x \) or \( y \) in terms of the other. By understanding and manipulating these equations, we can solve for unknown values.
The key to working with linear equations is to recognize that each solution is a point on a plane where the lines intersect. If you have more than one linear equation, as in this system, you are working with multiple lines that may or may not intersect to offer a solution.
Algebraic Manipulation
Algebraic manipulation is a fundamental skill in solving equations. It involves rearranging equations to isolate a particular variable. In our problem, we started by manipulating the first equation to express \( x \) in terms of \( y \).
  • From \( ax + by = \frac{1}{a} \), we isolated \( x \) as \( x = \frac{1}{a^2} - \frac{by}{a} \).
  • This was done by subtracting \( by \) from both sides and then dividing by \( a \) to solve for \( x \).

Algebraic manipulation often requires a strategic approach, where you need to decide which variable is easiest to isolate. This also includes tactics such as adding, subtracting, multiplying, or dividing both sides of the equation by the same value.
Practicing these manipulations helps in simplifying complex expressions, thereby making the process of solving equations more straightforward and effective.
Solving Equations
Solving equations often involves working through a series of steps to find the value of unknown variables. In the system of equations provided, we tackled the problem by expressing one variable in terms of another and substituting it into the second equation.
  • First, \( x \) was found in terms of \( y \).
  • Then, this expression for \( x \) was substituted into the second equation, \( b^2x + a^2y = 1 \).
  • By simplifying this equation, we obtained \( y = \frac{a^3 - b^2}{a^3 - b^3} \).

With \( y \) calculated, we then substituted its value back into the expression for \( x \) to get \( x = \frac{a^3 - a^2b - b^4}{a^2(a^3 - b^3)} \). Each substitution and simplification step brings us closer to the answer, unraveling one variable after another.
Solving systems of equations is a methodical process. Each step serves to eliminate unknowns, aiming to find one value at a time, which ultimately allows for uncovering the entire set of solutions.

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

Find all values of \(x\) for which $$ \left|\begin{array}{lll} 1 & x & x^{2} \\ 1 & 1 & 1 \\ 4 & 5 & 0 \end{array}\right|=0 $$

Show that $$\left|\begin{array}{lll} a_{1}+A_{1} & b_{1} & c_{1} \\ a_{2}+A_{2} & b_{2} & c_{2} \\ a_{3}+A_{3} & b_{3} & c_{3} \end{array}\right|=\left|\begin{array}{lll} a_{1} & b_{1} & c_{1} \\ a_{2} & b_{2} & c_{2} \\ a_{3} & b_{3} & c_{3} \end{array}\right|+\left|\begin{array}{lll} A_{1} & b_{1} & c_{1} \\ A_{2} & b_{2} & c_{2} \\ A_{3} & b_{3} & c_{3} \end{array}\right|$$

(a) Compute the inverse of the coefficient matrix for the system. (b) Use the inverse matrix to solve the system. In cases in which the final answer involves decimals, round to three decimal places. $$\left\\{\begin{aligned} x+2 y+2 z &=3 \\ 3 x+y &=-1 \\ x+y+z &=12 \end{aligned}\right.$$

The matrices \(A, B, C, D, E, F,\) and \(G\) are defined as follows: $$ A=\left(\begin{array}{rr} 2 & 3 \\ -1 & 4 \end{array}\right) \quad B=\left(\begin{array}{rr} 1 & -1 \\ 3 & 0 \end{array}\right) \quad C=\left(\begin{array}{ll} 1 & 0 \\ 0 & 1 \end{array}\right) $$ $$\begin{aligned} &D=\left(\begin{array}{rrr} -1 & 2 & 3 \\ 4 & 0 & 5 \end{array}\right) \quad E=\left(\begin{array}{rr} 2 & 1 \\ 8 & -1 \\ 6 & 5 \end{array}\right)\\\ &F=\left(\begin{array}{rr} 5 & -1 \\ -4 & 0 \\ 2 & 3 \end{array}\right) \quad G=\left(\begin{array}{ll} 0 & 0 \\ 0 & 0 \\ 0 & 0 \end{array}\right) \end{aligned}$$ In each exercise, carry out the indicated matrix operations if they are defined. If an operation is not defined, say so. $$D C$$

A parabola \(y=a x^{2}+b x+c\) passes through the three points \((1,-2),(-1,0),\) and (2,3) (a) Write down a system of three linear equations that must be satisfied by \(a, b,\) and \(c\) (b) Solve the system in part (a). (c) With the values for \(a, b,\) and \(c\) that you found in part (b), use a graphing utility to draw the parabola \(y=a x^{2}+b x+c .\) Find a viewing rectangle that seems to confirm that the parabola indeed passes through the three given points. (d) Another way to check your result in part (b): Apply the quadratic regression option on a graphing utility after entering the three given data points \((1,-2),(-1,0),\) and \((2,3) .\) (This is a valid check because, in general, three noncollinear points determine a unique parabola.)

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.