Solving Systems by Elimination HW

4x + 8y = 20

-4x + 2y = -30

Which variable will be eliminated?

• The x

• The y

• Both x and y

• Neither x or y

 $3x-2y=12$  

 $2x+2y=-2$  

What variable will eliminate in the system? 

• x

• y

• both

• neither

     $7x+5y=-12$  
 $10x+5y=5$  
What does the second equation need to be multiplied by to get the y's to eliminate?

• 5

• 0

• -1

• 2

 $-8x+y=20$  
   $4x-3y=5$  
What does the second equation need multiplied by so that the x's will eliminate?

• 2

• -1

• 4

• 0

What would be the equation for the next step in solving the system? (combine the equations)
    $2x-y=-15$   
 $-2x-4y=30$  

•  $-3y=-45$  

•  $-5y=-45$  

•  $3y=15$  

•  $-5y=15$  

What would be the first step in finding the solution with elimination?

4x + 3y = 1

x - 3y = -11

• cross out the 3y and -3y

• cross out the 4x and x

• change all the signs of the second equation

• add 1 and -11

What do you have to multiply the first equation by to have the x's be opposite and the same?

• 3

• 2

• -2

• -3

 $3x-2y=12$  

 $2x+2y=-2$  

What variable will eliminate in the system? 

• x

• y

• both

• neither

Solve the system by elimination:
 $x+y=6$  
 $6x-y=1$  

• (3, 3)

• (1, 5)

• (1, 3)

• (7, -1)