Systems of Equations - Elimination

What is your lunch number?

Solve by elimination:
7x + y = -9
-3x - y = 5

• No solution
• (1,8)
• (-2,-3)
• (-1,-2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Which variable will be "eliminated" by adding the equations together?

-2x -3y = 11

2x - 3y = -14

• x

• y

• Both

• None

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve using elimination. 
 4x + 8y = 20
-4x + 2y = -30

• (-7,1)
• Infinite Many Solutions

• (-2,5)
• (7,-1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

−4x − 4y = 0
4x + 4y = 0 

• (−6, −4) 
• Infinite Many Solutions  

• (−6, 10) 
• (6, 4) 

Tags

CCSS.8.EE.C.8B

• Add the x terms in the two equations and the y terms in the two equations so you get 3x + 8y = 11

• Multiply all terms in the top equation by 9 because the second equation ends with a 9.

• Isolate a variable in the first equation and substitute.

• Multiply all terms in the top equation
  by 2 so that the
  x-coefficients match.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

How many solutions does the following system have?

-9x - 3y = -10

36x + 12y = 0

• No Solution

• One

• Infinitely many

• Two

Tags

CCSS.8.EE.C.8B

Solve the system by elimination.

−6x + 6y = 0

9x − 8y = 4

• (4, −9)

• Infinite number of solutions

• (−9, 4)

• (4, 4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Identify the solution to this system of equations.

• (4, -1)
• (-1, 4)
• (-4, 1)
• (-4, -1)

Tags

CCSS.8.EE.C.8B

Determine how many solutions the system has.
(Hint:  Both lines are graphed over each other)

• One Solution
• No solution
• Infinitely Many Solutions
• I am Spartacus!

Tags

CCSS.8.EE.C.8A