Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
7. Systems of Equations & Matrices
Two Variable Systems of Linear Equations
Problem 39a
Textbook Question
In Exercises 31–42, solve by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets. x/4 - y/4 = −1 x + 4y = -9
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1
Step 1: The first step is to simplify the equations. The first equation can be simplified by multiplying both sides by 4 to get rid of the fractions. This will give us x - y = -4.
Step 2: Now we have two equations: x - y = -4 and x + 4y = -9. We can solve this system of equations using either substitution or elimination method. Let's use the elimination method. To do this, we need to make the coefficients of y the same in both equations. We can multiply the first equation by 4 to achieve this. This gives us 4x - 4y = -16.
Step 3: Now we have two new equations: 4x - 4y = -16 and x + 4y = -9. We can add these two equations together. The y terms will cancel out, leaving us with an equation in terms of x.
Step 4: Solve the resulting equation from step 3 for x.
Step 5: Substitute the value of x obtained in step 4 into one of the original equations to find the value of y.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Systems of Equations
A system of equations consists of two or more equations with the same set of variables. The solution to the system is the set of values that satisfy all equations simultaneously. Systems can be classified as consistent (having at least one solution) or inconsistent (having no solutions). Understanding how to manipulate and analyze these equations is crucial for finding solutions.
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Types of Solutions
In the context of systems of equations, solutions can be classified into three categories: a unique solution, no solution, and infinitely many solutions. A unique solution occurs when the lines represented by the equations intersect at a single point. No solution arises when the lines are parallel, while infinitely many solutions occur when the equations represent the same line, leading to an infinite number of intersection points.
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Set Notation
Set notation is a mathematical way to describe a collection of objects, often used to express the solution sets of equations. For example, a unique solution can be expressed as a single ordered pair (x, y), while infinitely many solutions may be represented using parameterization or interval notation. Understanding how to use set notation is essential for clearly communicating the nature of the solutions found in a system of equations.
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