Elimination!

Elimination

(Or tests!)

​ 2x - 4y = -10
3x + 4y = 5

Target Eliminated

Drag and Drop

Solve the system by elimination.

3x + y = 19

2x - y = 6

What do you get when you add the equations together?

​

Placeholder

x +​

Placeholder

y =​

Placeholder

Drag these tiles and drop them in the correct blank above

5

0

25

1

2

13

Math Response

Solve the system by elimination. What is the value of x?

3x + y = 19

2x - y = 6

Type answer here

Correct Answer: 5

Deg^°

Rad

Math Response

This is the same system from the previous slide. If x=5, what does y equal?

3x + y = 19

2x - y = 6

Type answer here

Correct Answer: 4

Deg^°

Rad

​2x + 6y = 6
2x - y = -8

Target Eliminated

Multiple Choice

Solve the system by elimination. If we target the y's, what should we multiply the second equation by?

x + 6y = 17

x - 3y = 8

• -1

• 2

• -2

• 6

Multiple Choice

Solve the system by elimination. Let's multiply the second equation by 2. What will the new equation be?

x + 6y = 17

x - 3y = 8

• 2x - 3y = 8

• 2x - 5y = 10

• 2x - 6y = 16

• 2x - 2y = 12

Drag and Drop

Here's our new system. Which of the answer choices shows the correct way to add the two equations?

x + 6y = 17

2x - 6y = 16

​

Placeholder

x ​ ​ + ​

Placeholder

y =​ ​

Placeholder

Drag these tiles and drop them in the correct blank above

0

3

33

1

2

-1

-2

-3

32

17

Multiple Choice

We've added our equations, and now we have:

3x + 0y = 33

We can simplify that into:

3x = 33

How can I get 3 by itself?

• Subtract 33 - 3

• Divide by 3

• Add 33 + 3

• Drop the 3

Math Response

3x = 33

So, what does x equal?

Type answer here

Correct Answer: 11

Deg^°

Rad

Multiple Choice

x + 6y = 17

2x - 6y = 16

Which of these shows the correct way to plug x = 11 into the second equation?

• 2(11) - 6y = 16

• 2x - 6(11) = 16

• 11 - 6y = 16

• 2x - 11 = 16

Reorder

After we plug in x = 11,

2(11) - 6y = 16,

what are the next steps?

• Simplify 2(11)

  22 - 6y = 16

• Subtract 22 from both sides

  -6y = -6

• Divide both sides by -6

1

2

3

• 1
• 2
• 3

Math Response

2(11) - 6y = 16

So what is the value for y?

Type answer here

Correct Answer: 1

Deg^°

Rad

​3x + 8y = 7
2x - 2y = -10

Target Eliminated

Multiple Choice

A student solves the system and gets to the answer 0 = 0. What does this tell you about the system?

• The answer tells you x and y, so the solution: (0, 0)

• The answer is a false statement, so

  there is no solution

• The answer is a true statement, so there are infinitely many solutions

Multiple Choice

A student solves the system and gets to the answer 0 = -5. What does this tell you about the system?

• The answer tells you x and y, so the solution: (0, -5)

• The answer is a false statement, so

  there is no solution

• The answer is a true statement, so there are infinitely many solutions

Match

Please match each system to the type of solution

No solution

Infinitely many solutions

One solution

• No solution

• Infinitely many solutions

• One solution