Intro to Elimination Systems

Which variable would be easiest to eliminate?

4x + 8y = 20

−4x + 2y = −30

• x because they have equal coefficients but opposite sign

• y because they have equal coefficients but opposite sign

Which variable would be easiest to eliminate?

• x because they have equal coefficients but opposite sign

• y because they have equal coefficients but opposite sign

Which variable would be easiest to eliminate?

• you cannot solve this using eliminiation

• x because they have equal coefficients but opposite sign

• y because they have equal coefficients but opposite sign

What could we multiply the 1st equation by to eliminate the x variable?

• 3

• 4

• -3

• -4

What could we multiply the 1st equation by to eliminate the y variable?

• 3

• 4

• -3

• -4

What could we multiply the 1st equation by to eliminate the x variable?

x + 6y = 17

x - 3y = 8

• 1

• -1

• 3

• 6

What could we multiply the 2nd equation by to eliminate the y variable?

x + 6y = 17

x - 3y = 8

• 1

• -1

• 2

• 3

Solve the system:

3x + y = 19

2x - y = 6

• (5, 14)

• (4, 5)

• (5, 4)

• (14, 5)

How many solutions will this system have? 

• No solution

• One Solution

• I Don't Know

• Infinitely Many Solutions

Solve by elimination:  4x + 8y = 20

−4x -8y = −30

• (-1, 7)

• (-7, 1)

• no solutions

• infinite solutions