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PPT – Another method for solving systems of equations is elimination. Like substitution, the goal of elimination is to get one equation that has only one variable. To do this by elimination, you add the two equations in the system together. PowerPoint presentation | free to download - id: 78ad61-NzQ3Z

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Another method for solving systems of equations

is elimination. Like substitution, the goal of

elimination is to get one equation that has only

one variable. To do this by elimination, you add

the two equations in the system together.

Solving Systems of Equations by Elimination

Write the answers from Steps 2 and 3 as an

ordered pair, (x, y), and check.

Step 4

Example 1 Elimination Using Addition

3x 4y 10

Solve by elimination.

x 4y 2

Write the system so that like terms are aligned.

Add the equations to eliminate the y-terms.

Simplify and solve for x.

Example 1 Continued

Write one of the original equations.

Substitute 2 for x.

Write the solution as an ordered pair.

Check It Out! Example 2

y 3x 2

Solve by elimination.

2y 3x 14

Write the system so that like terms are aligned.

Add the equations to eliminate the x-terms.

Simplify and solve for y.

Check It Out! Example 2 Continued

Write one of the original equations.

Substitute 4 for y.

Write the solution as an ordered pair.

When two equations each contain the same term,

you can subtract one equation from the other to

solve the system. To subtract an equation add the

opposite of each term.

Example 3 Elimination Using Subtraction

2x y 5

Solve by elimination.

2x 5y 13

2x y 5

Add the opposite of each term in the second

equation.

(2x 5y 13)

Eliminate the x term.

Simplify and solve for y.

Example 3 Continued

Write one of the original equations.

Substitute 3 for y.

Simplify and solve for x.

Write the solution as an ordered pair.

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Check It Out! Example 4

3x 3y 15

Solve by elimination.

2x 3y 5

Add the opposite of each term in the second

equation.

Eliminate the y term.

Simplify and solve for x.

Check It Out! Example 4 Continued

Write one of the original equations.

Substitute 4 for x.

Simplify and solve for y.