Elimination Method of System of Equations

Solve the system by elimination.
  5x + 8y = -12
3x + 5y = -7

• (1, -10)

• No solution

• (-4, 1)

• (1, 10)

6x + 7y = -15

6x - 2y = 12

which variable should be "eliminated" first?

• x

• y

6x + 7y = -15

6x - 2y = 12

Will you add or subtract to "eliminate" the x variable?

• add

• subtract

Determine how many solutions the system has.

• One Solution

• No Solutions

• Infinitely Many Solutions

• Mikey is my friend.

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!

Solve using elimination.
7x + 2y = 24
8x + 2y = 30

• (6,-9)

• (-9,6)

• No solution

• Infinite number of solutions

Homer sells tickets for admission to your school play and collects a total of $104. Admission prices are $6 for adults and $4 for children. He sold 21 tickets total. Solve the system:
x + y = 21
6x + 4y = 104

• (10, 11)

• (12, 9)

• (11, 10)

• (9, 12)

5x - y = 12

3x + y = 4

which variable should be "eliminated" first?

• x

• y

5x - y = 12

3x + y = 4

Will you add or subtract to "eliminate" the y variable?

• add

• subtract

What action can you take to create equivalent coefficients so that the "elimination" method can be used?

• Multiply the top equation by 4

• Multiply the top equation by 2

• Multiply the bottom equation by 2

• Multiply the bottom equation by 4