Solving a System of Equations by Elimination

Solve by elimination:
3x + 7y = 23
-3x - 7y = -17

• No solution

• Infinite number of solutions

• (-3,3)

• (3,3)

Solve the system by elimination.
4x + 12y = −1
−3x − 9y = 0 

• (10, 1) 

• (−10, −1) 

•  (10, −1) 

•  No solution 

________________ is a set of two or more equations that have the same variables.

• solution of a system

• elimination method

• system of equations

• table

Solve using elimination. 
−4x − 4y = 0
  8x + 8y = 0 

• (−6, −4) 

• Infinite number of solutions  

• No solutions

• (6, 4) 

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

• (1, -10)

• No solution

• (-4, 1)

• (1, 10)

a method to solving a system of equations by getting rid of one of the variables first to solve for the other variable. 

• Systems by Graphing

• Systems by Substitution

• Systems by Elimination

• Systems by Drawing

Solve the system by elimination.

7x - y = -10

-7x + 5y = -6

• (-2, -4)

• (-2, -1)

• (-4, -1)

• (6, -8)

What is the solution to the system?

• No solution

• (0, 2)

• (0, -4)

• (3, -3)

Alexandra finds that she can give 3 haircuts and 2 hair dyes in 315 minutes. Giving 2 haircuts and 4 hair dyes takes 450 minutes.  Which system of equations represents the situation?

• 3x + 2y = 315
  2x + 4y = 450

• 3x + 2y = 450
  2x + 4y = 315

• 2x + 2y = 315
  3x + 4y = 450

When using any of the 3 methods to solve a system of linear equations the resulting solution is the same no matter which method is used.

• True; using any method will result in the correct solution.

• False; the solution varies because the solution depends on which method is used.