Solving Systems of Equations By Elimination (Plus Review!)

Identify the solution to this system of equations.

• (4, -1)
• (-1, 4)
• (-4, 1)
• (-4, -1)

Which of the following is NOT a method to solve systems?

• Elimination
• Distribution
• Substitution
• Graphing

The solution (x, y) to a system of equations is the point where they...? 

• Run off the graph
• Don't touch
• Intersect
• Exist

Alex and Billy are running laps. According to the graph, how long will it take for the two boys to run the same distance?

• 20 minutes
• 15 minutes
• 10 minutes
• 5 minutes

The first step in solving using the substitution method is __________.

• get x by itself
• get y by itself
• get either variable by itself
• add the equations together

What is the first step to solving this system by elimination?:
x + 9y = 8
-6x - 9y = -3

• Solve the first equation for x.

• Subtract the equations.

• Add the equations together.

• Multiply the first equation by 9.

What is the first step to solving this system by elimination?:

7x-9y=29

7x+2y=-15

• Add the equations to eliminate the x-variable.

• Subtract the equations to eliminate the x-variable.

• Add the equations to eliminate the y-variable.

• Subtract the equations to eliminate the y-variable.

Find the value of x for the following system:
7x+y=-9

-3x-y=5

• 2

• 1

• -2

• -1

Find the value of y for the following system, given that x = -1:
7x+y=-9

-3x-y=5

• -2

• 1

• -2

• -1

3x + y = –14

–2x – y = 9

Which method would be best for solving this system?

• Substitution

• Elimination