Systems of Equations

Give the solution to the system.

• (3,1)
• (1,3)
• (-1,3)
• (1, -3)

Tags

CCSS.8.EE.C.8B

How many solutions?

• One Solution
• No solution
• Infinitely Many Solutions

Tags

CCSS.8.EE.C.8A

What variable do you eliminate?

4x + 8y = 20

−4x + 2y = −30

• X because they have opposite signs

• Y because they have opposite signs

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Julie is asked to solve the system below by elimination. Which of the following steps would be the BEST way to begin?

• 
• 
• 
• 

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

A system of equations with infinitely many solutions will have lines that...

• are the same

• are parallel and never touch

• cross in one place

Tags

CCSS.8.EE.C.8A

Solve the system

4x + 8y = 20

-4x + 2y = -30

• (-7,1)

• (2,-5)

• (-2,5)

• (7,-1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

• x 

• y 

• either one, they are the same

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

• 4

• 2

• 1

• -2

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

• The x variable would be easiest to eliminate

• The y variable would be easiest to eliminate

• We would multiply top equation by 2

• Would multiply the bottom equation by 2

• This system has no solution

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6