7.4. 5x + 2y = 16 5x + 2y = 16 3x – 4y = 20 3x – 4y = 20 In this linear system neither variable...
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Transcript of 7.4. 5x + 2y = 16 5x + 2y = 16 3x – 4y = 20 3x – 4y = 20 In this linear system neither variable...
![Page 1: 7.4. 5x + 2y = 16 5x + 2y = 16 3x – 4y = 20 3x – 4y = 20 In this linear system neither variable can be eliminated by adding the equations. In this linear.](https://reader036.fdocuments.in/reader036/viewer/2022082404/5697bfd21a28abf838cab9b8/html5/thumbnails/1.jpg)
Elimination Method Cont.
7.4
![Page 2: 7.4. 5x + 2y = 16 5x + 2y = 16 3x – 4y = 20 3x – 4y = 20 In this linear system neither variable can be eliminated by adding the equations. In this linear.](https://reader036.fdocuments.in/reader036/viewer/2022082404/5697bfd21a28abf838cab9b8/html5/thumbnails/2.jpg)
Oh no!5x + 2y = 16
3x – 4y = 20
In this linear system neither variable can be eliminated by adding the equations.
For systems like this you can multiply one or both equations by a constant so adding will result in elimination.
![Page 3: 7.4. 5x + 2y = 16 5x + 2y = 16 3x – 4y = 20 3x – 4y = 20 In this linear system neither variable can be eliminated by adding the equations. In this linear.](https://reader036.fdocuments.in/reader036/viewer/2022082404/5697bfd21a28abf838cab9b8/html5/thumbnails/3.jpg)
What to do.
Step P: Multiply one or both equations.
Step 1: Add the equations.
Step 2: Solve for variable.
Step 3: Substitute into either equation and solve for other variable.
5x + 2y = 163x – 4y = 20
2( )
10x + 4y = 32 3x – 4y = 2013x = 52
13x = 5213 13
X = 4
3(4) – 4y = 2012 – 4y = 20-4y = 8Y = -2
(4,-2)
5x + 2y = 163x – 4y = 20
![Page 4: 7.4. 5x + 2y = 16 5x + 2y = 16 3x – 4y = 20 3x – 4y = 20 In this linear system neither variable can be eliminated by adding the equations. In this linear.](https://reader036.fdocuments.in/reader036/viewer/2022082404/5697bfd21a28abf838cab9b8/html5/thumbnails/4.jpg)
Multiplying both
Step P: Multiply one or both equations.
Step 1: Add the equations.
Step 2: Solve for variable.
Step 3: Substitute into either equation and solve for other variable.
2x – 9y = 17x – 12y = 23
-4( ) 3( )
-8x + 36y = -421x - 36y = 6913x = 65
13x = 6513 13
X = 5
2(5) – 9y = 110 – 9y = 1-9y = -9Y = 1
(5,1)
2x – 9y = 17x – 12y = 23
![Page 5: 7.4. 5x + 2y = 16 5x + 2y = 16 3x – 4y = 20 3x – 4y = 20 In this linear system neither variable can be eliminated by adding the equations. In this linear.](https://reader036.fdocuments.in/reader036/viewer/2022082404/5697bfd21a28abf838cab9b8/html5/thumbnails/5.jpg)
Practice Problems
6x – 2y = 1-2x + 3 = -5
2x + 5y = 33x + 10y = -3
3x – 7y = 59y = 5x + 5