Solve Linear Equations Using Substitution and Elimination

Solve the system by substitution:

x - y = 6

y - 2x = - 5

• (1,3)

• (-1,3)

• (-1,-7)

• (1,-7)

Solve by elimination:
7x+y=-9

-3x-y=5

• No solution

• (1,8)

• (-2,-3)

• (-1,-2)

Solve by elimination:
-x+2y=17

2x+2y=-10

• ARN

• (-9,4)

• (-9,-4)

• (9,-4)

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

What is the first step in solving a system by Substitution?

• Make sure both equations are in standard form.

• Make sure at least one equation is solved for one variable.

• Make sure both equations are in slope-intercept form.

• Make sure both equations can be solved.

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

a method of solving a system of equations by taking a variable out and replacing it with an expression.

• Systems by Graphing

• Systems by Substitution

• Systems by Elimination

• Systems by Drawing

What is the solution to this system of equations? Solve by substitution or graphing.

• (7, -8)

• (-7, 8)

• (-7, -8)

• (7, 8)

Solve the system by substitution.

−x + 5y = 12

y = −2x − 2

• (−2, −7)

• (−2, 2)

• (−2, −2)

• (2, −2)

What is the solution to the system?

• No solution

• (0, 2)

• (0, -4)

• (3, -3)