Introduction to Elimination

What variable will be eliminated? 
4x+9y=28
-4x-y=-28

• x
• y

What variable will you be eliminating? 
10x + 9y= 36
-4x - 9y= 10

• y
• x

What variable do you eliminate? 
5x+7y=23
-5x-7y=-17

• x
• y

What is the value of x? 
2x-4y=20
9x+4y=2

• 2
• 22

What is your value of x? 
7x+y=9
3x-y=21

• 3
• 30

What do you have to do before you can solve this system by elimination? 
4x + 4y = 4
3x + 4y = 10

• multiply one equation by -1
• Multiply one equation by 1

What variable do you eliminate? 
-x + 2y = 17
2x - 2y = -10

• x
• y

What is your value of x? 
2y + 5x = 8
-2y + 3x = 8

• 1
• 8

What do we need to do before we can solve this by elimination?:
9x - 4y = 7
x - 4y = -17

• Multiply one equation by -1 
• Multiply one equation by 1

Solve by elimination 
4x - 4y = 0 
 -2x + 4y = 2

• (1, 1) 
• (0,0)