Systems Elimination

Select the best option below for solving this system of equations using elimination.

• Multiply the first equation by -1.

• Multiply the first equation by -2.

• Solve the second equation for y, then substitute that expression in for y in the other equation.

• No changes are necessary - this system is perfectly setup for elimination.

You decide to solve the below system of equations using elimination and first want to eliminate the x variable. Which option below would be the best first step? -4x+9y=-17 3x-4y=10

• Multiply the first equation by 4 and the second equation by 9.

• Multiply the first equation by -3 and the second equation by 4.

• Multiply the first equation by 3 and the second equation by -4.

• Multiply the first equation by 3 and the second equation by 4.

Solve by elimination
-2x + 6y = 16
-4x - 3y = 2

• (2,2)

• (-2, -2)

• (-2,2)

• (2,1)

Solve by elimination:
7x+y=-9

-3x-y=5

• No solution

• (1,8)

• (-2,-3)

• (-1,-2)

What is the solution to this system?

• (-2, -2)

• (2, -2)

• (-2,2)

• (2, 2)

 4x + 8y = 20
-4x + 2y = -30

• (-7,1)

• (2,-5)

• (-2,5)

• (7,-1)

You can solve systems using these methods:

• graphing, substitution, and elimination

• rearranging, thinking, and guessing

• only by graphing

Which method may be fastest if both equations are in standard form with the x's and y's lined up?

• graphing

• substitution

• elimination

Erin is 3 years younger than twice Alex's age. Their ages combined are 33 years. How old are Alex and Erin. If x=Erin's age and y=Alex's age, choose the system that matches the situation.

• x + y = 33
  y = 2x - 3

• x + y = 33
  x = 2y - 3

• x + y = 33
  x = 3 - 2y

• x + y = 3
  x = 33 - 2y

Nancy went to the grocery story. On Monday she purchased 4 apples and 6 bananas for a total of $13. On Wednesday she purchased 3 apples and 7 bananas for a total of $13.50. Which system of equations represents the situation?

• 4x + 6y = 3

  13.5x - 13y = 6

• x + y = 4

  x - y = 6

• 4x + 6y = 13

  3x + 7y = 13.5

• 4x - 6y = 13

  3x - 7y = 13.5