Making Substitution Happen!

Making Substitution Happen!

To be able to solve a system of equations by SUBSTITUTION, exactly ONE of the two equations has to be written as x = or y =

This equation is called the Substitution Equation and will be substituted into the other equation in place of x or y

Multiple Choice

Which is the Substitution Equation?

A. 2x + y = 5

B. y = 2x - 11

• A

• B

Multiple Choice

Which is the Substitution Equation?

A. x = - 3y -13

B. 4x + 2y = 4

• A

• B

Multiple Choice

Which is the Substitution Equation?

A. x = 2y - 3

B. x + 3y = 22

• A

• B

Multiple Choice

Which is the Substitution Equation?

A. y = 2x + 1

B. 4x + y = 7

• A

• B

How to MAKE a Substitution Equation

If neither equation in your system is written as y = or x = then you have to choose one of the equations that's easy to rewrite as y = or x =

It's easy -

Pick the equation that has an x or y with no number in front of it; then +/- to get that variable by itself

Multiple Choice

Which is the Substitution Equation AND how should it be re-written?

A. x - 3y = -13

B. 4x + 2y = 4

• A. x = 3y + 13

• B. 4x= 2y - 4

• A. x = 3y - 13

• B. 4x = -2y + 4

Multiple Choice

Which is the Substitution Equation AND how should it be rewritten?

A. 3x + 2y = 16

B. 7x + y = 19

• A. 2y = 16 + 3x

• A. 3x = 16 - 2y

• B. y = 19 + 7x

• B. y = 19 - 7x

Multiple Choice

Solve by substitution

x = 2y

x + y = 6

• (1, 5)

• (-1, 2)

• (6, 3)

• (4, 2)

Multiple Choice

Solve the following system:

 $y=5x-2$  

 $-3x+6y=-12$  

•  $\left(0,\ -2\right)$  

•  $\left(0,\ 2\right)$  

•  $\left(-2,\ 0\right)$  

•  $\left(2,\ 0\right)$  

Multiple Choice

Solve this system of equations. 
y = 2x + 1
y = 4x - 1

• (1,3)
• (-1,-3)
• (-1,3)
• (3,1)

Multiple Choice

This system has _____ solutions

• 0

• 1

• 2

• Infinitely many

Multiple Choice

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

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

Multiple Choice

How many solutions will this system have?

• No Solution
• Infinitely Many Solutions
• No Clue
• One solution