Solving Equations with Elimination

Solve by elimination:

10x -14y = -4

-7x + 7y = 0

• (1, 1)

• (-1, 1)

• (1, -1)

• (-1, -1)

-3x - 3y = -9

-9x -9y = -27

• (8, -10)

• (-8, -10)

• Infinitely Many Solutions

• No solution

What can we do so that they match?

• Let's subtract so that we can get matching numbers!

• Let's multiply #2 by 2 to match #1!

• Let's add so we can get matching numbers!

What is the result of this?

• 6x - 3y

• 40x + 4y

• 14x + 5y

Solve the system by elimination.
−6x + 6y = 0
9x − 8y = 4

• (4, −9)
  

• Infinite number of solutions 

• (−9, 4)
  

• (4, 4) 

Solve by elimination
4x-6y= -6
-2x-12y= -12

• (0,1) 

• (1,0)

• (1,1)

• (2,1)

Solve by elimination
-12x-4y= -8 
  -6x-2y= -4

• no solution 

• (0,0)

• infinite solutions 

• (4,0)

4x + 8y = 20
−4x + 2y = −30

• (-1, 7)

• (-7, 1)

• (7, -1)

• (1, -7)

x − y = 11
2x + y = 19

• (-1, 10)

• (30, 19)

• (19, 30)

• (10, -1)

5x + y = 9
10x − 7y = −18

• (4, -11)

• (1, 4)

• (-1, 14)

• (-4, 29)