Solving Systems by Elimination

Solve by elimination:
4x+9y=28
-4x-y=-28

• (-7,0)
• (6,0)
• (-6,0)
• (7,0)

Solve by elimination:

7x+y=-9

-3x-y=5

• No solution

• (-1,8)

• (-2,-3)

• (-1,-2)

Solve by elimination:
4x+4y=4

3x+4y=10

• (7,-6)
• (-6,7)
• (6,7)
• (7,6)

Solve by elimination

4x-6y= -6

-2x-12y= -12

• (0,1)

• (1,0)

• (1,1)

• (0, 2)

Solve by elimination 
2x+9y= -7 
6x-3y= 9 

• (-1, -1) 
• (2,-1)
• (1,1)
• (1,-1)

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

8x + 14y = 4

-6x - 7y = -10

• (4, -2)

• (-2, 4)

• (0, 3)

• (-4, -2)

Last season two running backs on the Steelers football team rushed a combined total of 1550 yards.  One rushed 4 times as many yards as the other.  Let x and y represent the number of yards each individual player rushed. Which system of equations could be used? 

• x + y = 1550
  y  = 4x
• x + y = 1550
  y = x + 4
• y - x = 1550
  y = 4x
• y = 1550 + x
  y = x + 4

Ride and Transport are two new ride sharing companies in Colorado. Ride is charging $2 for pick up fees and then $2.50 per mile (m). Transport is charging only $2.70 per mile. How many miles will it take for both companies to charge the same amount (c)? Which system of equations could be used? 

• C = 2m + 2.50

  C = 2.70

• C = 2 + 2.50 m

  C = 2.70m

• C = 2.50 m + 2.70 m

  C = 2

• C = 2.50 + 2.70

  C = 2m