How to Eliminate
Multiplying Equations by Numbers
What to Multiply by
Practice Problems
100

What must you do before you add or subtract your equations?

Line up your terms / check if you will eliminate a term / Multiply your equation if needed

100

Multiply 2x + 8y = 4 by 3

6x + 24y = 12

100

What should you multiply the top equation by so the x value will be eliminated when you add?

3x + 298y = 999

-6x - 654y = 0

2

100

Use the elimination method to find the solution to the system of equations:

5x + y = 11

-5x + 4y = 19

x = 1

y = 6

200

How many steps are there in the elimination method?

5

200

Multiply 4x - 6y = 1 by 7

28x -42y = 7

200

What should you multiply the top equation by so the y value will be eliminated when you add?

554x -5y = 420

345x + 20y = 69

4

200

Use the elimination method to find the solution to the system of equations:

10x - 10y = 10

-5x + 20y =25

x = 3

y = 2

300

What is step 4 to the elimination method?

Solve for the remaining variable

300

Multiply 3x + 3y = 8 by 5

15x + 15y = 40

300

What should you multiply the top equation by so the x value will be eliminated when you subtract?

3x + 7083y = 666

18x + 2023y = 1234567

6

300

Use the elimination method to find the solution to the system of equations:

5x - 6y = 11

3x + 2y = 29

x = 7

y = 4

400

When using the elimination method what are you trying to find (what will your answer be?)

The solution to the system

400

Multiply 10x + 4y = 3 by -2

-20x - 8y = -6

400

What should you multiply the top equation by so the y value will be eliminated when you subtract?

88x - 5y = 0

54x + 5y = 12

-1

400

Use the elimination method to find the solution to the system of equations:

2x + 2y = 22

-4x + 10y = -2

x = 8

y = 3

500

What do you do if your equations will not eliminate if you were to add or subtract them?

Multiply an equation by a number so that they will eliminate

500

Multiply 7x + 9y = 3 by -1

-7x - 9y = -3

500

What should you multiply the top equation by so the x value will be eliminated when you subtract?

45x + 975y = 33

45x + 200y = 1

Nothing

500

Use the elimination method to find the solution to the system of equations:

8x + 5y = 26

-8x + 10x = -4

x = 2

y = 2