Math 8: Systems Test Study Guide

Which of the following is NOT a common method for solving systems of linear equations?

• Elimination

• Substitution

• Graphing

• Guesswork

Tags

CCSS.8.EE.C.8

The solution is the _ _ _ _ _ _ _ _ _ _ _ _ point of the graphs of the equations.

(Select ALL that apply): Which operation(s) can you use to eliminate a term in elimination method?

• Add if they are the opposites

• Subtract if they are the same

• Divide no matter what

• Add if they are the same

• Subtract if they are opposites

What is the first step in using the elimination method to solve a system of equations?

• Identify a variable to eliminate

• Graph the equations

• Substitute one equation

• All of the above

What is the first step in using the substitution method to solve a system of equations?

• One equation must be solved for x or y.

• Eliminate one variable by substitution.
• Graph both equations on a coordinate plane.
• Add the two equations together.

What is the appropriate order for solving the system of equations using substitution?

y = x - 1 and y = 4x + 8

• y = -4

• Solve for x using inverse operations.

• x = -3

• Write an equation to show x - 1 = 4x + 8

• Substitute -3 into one of the original equations to solve for y.

Match the following systems with the elimination strategy.

• SUBTRACT to eliminate y then solve for x

• 2.3x - 6.4y = 9.77

  2.3x + 4.6y = 7.99

• ADD to eliminate y then solve for x

• 2.3x + 6.4y = -9.77

  -2.3x - 6.4y = 7.77

• ADD, both eliminated,

  0 = -2

  no solutions

• 2.3x - 6.4y = 9.77

  -2.3x - 4.6y = 7.99

• SUBTRACT to eliminate x then solve for y

• 2.3x - 6.4y = 9.77

  3.2x + 6.4y = 7.99

• ADD to eliminate x then solve for y

• 2.3x - 6.4y = 9.77

  3.2x - 6.4y = 7.99

Reorder the following steps to show the process to solve using substitution.

y = 3x - 1

4x - y = 4

• 1x + 1 = 4

• 4x - 3x + 1 = 4

• 4x - (3x - 1) = 4

• x = 3

• y = 3(3) - 1

  y = 8

What do these two equations add to after using the first step of elimination?

3x - 6y = 12

2x + 6y = 18

• 5x = 30
• 4x = 24
• 6x = 36
• 3x = 15

Match the following solutions to the graphs.

• Infinite Solutions

• 
• No Solution

• 
• (2, 1)

• 
• (3, -2)

•