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Ch. 5 - Systems of Equations and Inequalities
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 6, Problem 21

In Exercises 19–30, solve each system by the addition method. 2x + 3y = 6 2x - 3y = 6
Exercise 21: Solve the system of equations 2x + 3y = 6 and 2x - 3y = 6 using the addition method.

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1
Write down the system of equations clearly: 2x+3y=62x3y=6.
Add the two equations together to eliminate y because the coefficients of y are opposites (+3y and -3y). This gives: (2x + 3y) + (2x - 3y) = 6 + 6.
Simplify the left side by combining like terms: 2x + 2x + 3y - 3y = 4x + 0 = 4x, and simplify the right side: 6 + 6 = 12. So the equation becomes 4x = 12.
Solve for x by dividing both sides by 4: x = \(\frac{12}{4}\).
Substitute the value of x back into one of the original equations to solve for y. For example, use 2x + 3y = 6, plug in x, and solve for y.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

System of Linear Equations

A system of linear equations consists of two or more linear equations with the same variables. The solution is the set of values that satisfy all equations simultaneously. Understanding how to interpret and represent these systems is fundamental to solving them.
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Addition Method (Elimination Method)

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Solving for Variables After Elimination

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