Systems by Elimination

Solve by elimination:

7x+y=-9

-3x-y=5

• No solution

• (1,8)

• (-1,-3)

• (-1,-2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve by elimination:
4x+9y=28
-4x-y=-28

• (-7,0)

• (6,0)

• (-6,0)

• (7,0)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve by elimination

-6x + 5y = 1

6x + 4y = -10

• (-1,7/5)

• (0,-1)

• (1,1)

• (-1,-1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve by elimination:
-9x - 4y = -20
5x + 4y = 4

• (-4,4)

• (4,4)

• (4,-4)

• (-4,-4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve by elimination:

-9x-4y=-20

5x+4y=4

• (-4,4)

• (4,4)

• (4,-4)

• (-4,-4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What do you do in #6?

• x

• Eliminate

• -12

• Divide by

• y

• Solve for...

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of equations by elimination: \[ \begin{cases} 2x + 3y = 6 \\ 4x - 3y = 12 \end{cases} \]

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system. Plot the solution on the graph.

2x + 9y = -7 
6x - 3y = 9 

Tags

systems

Solve by elimination:

7x + y = -9

-3x - y = 5

• No solution

• (1,8)

• (-1,-3)

• (-1,-2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What would be the first step in finding the solution using elimination?

2x + 2y = -2

3x - 2y = 12

• you cannot solve this using eliminiation

• cross out the 2x and 3x

• cross out the 2y and -2y

• change to slope intercept form and graph

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6