Systems of Equations

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

Tags

CCSS.HSA.CED.A.3

Christian had brochures printed for a new business venture. Christian originally ordered 4 boxes of black-and-white brochures and 3 boxes of color brochures, which cost a total of $134. After those ran out, Christian spent $120 on 3 boxes of black-and-white brochures and 3 boxes of color brochures. Which system represents this situation?

• x+y=134
  x+y=120

• 3x+3y=134
  4x+3y=120

• 4x+3y=134
  3x+3y=120

• 7xy=134
  6xy=120

Tags

CCSS.8.EE.C.8C

Rachel buys 3 tricycles and 4 bicycles for a total of $72. Joe bought 5 tricycles and 2 bicycles for $50.  Which system models this scenario?

• 3B + 4T = 72
  2T + 5B = 50

• 3T + 4B = 72
  5T + 2B = 50

• 3T + 4B = 50
  5T + 2B = 72

Tags

CCSS.8.EE.C.8C

Jon has a total of 25 quarters and dimes.  The amount of money he has is $5.65.  Which system models this scenario?

• Q + D = 25
  .25Q + .10D = 5.65

• Q + D = 5.65
  .25Q + .10D = 25

• .25Q + .10D = 25
  Q + D = 5.65

Tags

CCSS.HSA.CED.A.3

A farmer grows corn and lettuce.  He plans to plant 455 rows this year.  The number of rows of corn will be 2.5 times the number of rows of lettuce.  Which system models this scenario?

• L = 2.5C
  C + L = 455

• C + L = 2.5L
  C + L = 455

• C + L = 455
  C = 2.5L

Tags

CCSS.8.EE.C.8C

A 100 point test consists of 2 point questions and 5 point questions. There were 44 total questions on the test. Which system models this scenario?

• 2X + 5Y = 100
  X + Y = 44

• X + Y = 100
  2X + 5Y = 44

• 2X + 5Y = 100
  X + Y = 100

• X + Y = 44
  2X + 5Y = 44

Tags

CCSS.8.EE.C.8C

Maggie bought 2 shirts and 2 sweaters and spent $86.  Mia bought 3 shirts and 1 sweater and spent $81.  Which system models this scenario?

• 2X + 2Y = 81
  3X + Y = 86

• 2X + 2Y = 86
  3X + Y = 81

• X + Y = 86
  X + Y = 81

• 2X + 2Y = 167
  3X + Y = 167

Tags

CCSS.HSA.CED.A.3

Ralph makes $14 per hour plus a $20 stipend.  Melissa makes $12 per hour plus a $15 stipend.  Which system models this scenario?

• y = 14x + 15
  y = 12x + 20

• y = 20x + 14
  y = 15x + 12

• y = 14x + 20
  y = 12x + 15

Tags

CCSS.8.EE.C.8C

Sam has a total of 15 bikes and skateboards.  A bike has 2 wheels and a skateboard has 4 wheels, and she has a total of 40 wheels.  Which system models this scenario?

• B + S = 40
  2B + 4S = 15

• B + S = 15
  2B + 4S = 40

• B + S = 15
  4B + 2S = 40

Tags

CCSS.8.EE.C.8C

Ben ordered 20 total items consisting of pizza and sodas.  A pizza is $10, a soda is $2, and he spent a total of $72.  Which system models this scenario?

• 10P + 2S = 20
  P + S = 72

• P + S = 20
  2P + 10S = 72

• P + S = 20
  10P + 2S = 72

Tags

CCSS.HSA.CED.A.3