Solving Systems of Equations Using Substitution

How confident are you are solving a system of equations using substitution?

• I am rock SOLID!

• I am probably ok, but a few more examples wouldn't hurt.

• I still have a lot of questions.

• I will need help walking through that again.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What does

"solution to a system of equations"

mean?

• It's the point where both equations equal zero

• It's the point where graphs of both equations cross the y-axis

• It's the point that solves both equations at the same time

• It's the point where graphs of both equations cross the x-axis

Tags

CCSS.8.EE.C.8B

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

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system by substitution. 
3x − 2y = 7 
y = 2x − 7 

• No solution 
•  (7, 7)  
•  (−7, −7)  
•  (−7, −3)  

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system by substitution. 
y = 2x − 11 
2x − 8y = 4 

•  (6, 1)
• (6, −4)
• (6, −1)
• Infinite number of solutions  

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve this system of equations.

y = 2x + 1

y = 4x - 1

• (1,3)

• (-1,-3)

• (-1,3)

• (3,1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What are ALL the possible solutions to a System of Equations?

• One Solution

• Infinite Solutions

• No Solution

Tags

CCSS.8.EE.C.8B

Solve the following systems of equations using substitution:

2y + x = -15

x = 3y

• (-3, -9)

• (-9, -3)

• (-3, 9)

• (9, -3)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

• Student A

• Student B

• Neither student substituted correctly

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

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

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

Tags

CCSS.8.EE.C.8B