Systems of Equations

Define two variables, write a system of equations, then solve. The perimeter of a rectangle is 48 in. The width is 3 inches less than twice the length. Find the dimensions of the rectangle.

• 14 in. by 10 in.

• 9 in. by 15 in.

• 6 in. by 18 in.

• 12 in. by 12 in.

Tags

CCSS.8.EE.C.8C

Define two variables, write a system of equations, then solve. Sue plans to mix peppermints worth $1.20 per lb with chocolates worth $2.40 per lb to get a 40 lb mix that is worth $1.65 per lb. How much of each should she use?

• 25 lbs peppermints, 15 lbs chocolates

• 20 lbs peppermints, 20 lbs chocolates

• 15 lbs peppermints, 25 lbs chocolates

• 30 lbs peppermints, 10 lbs chocolates

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

In a pasture are horses and chickens if there are a total of 28 animals and 80 legs how many chickens and horses?

• 10 horses, 18 chickens
• 16 horses, 12 chickens
• 12 horses, 16 chickens
• 18 horses, 10 chickens

Tags

CCSS.8.EE.C.8C

The school that Stefan goes to is selling tickets to a choral performance. On the first day of ticket sales the school sold 3 senior citizen tickets and 1 child ticket for a total of $38. The school took in $52 on the second day by selling 3 senior citizen tickets and 2 child tickets. Which equations represents the system that could be used? 

• 1s + 3c = 38
  2s + 3c = 52
• 3s + 1c = 38
  3s + 2c = 52
• s + c = 38
  s + c = 52
• 3s + 3c = 38
  1s + 2c = 52

Tags

CCSS.HSA.CED.A.3

Dennis mowed his next door neighbor’s lawn for a handful of dimes and nickels, 80 coins in all.  Upon completing the job he counted out the coins and it came to $6.60.  Which system of equations could be used to find the exact number of dimes and nickels? 

• d + n = 6.60
  .10d + .05n = 80
• d + n = 80
  d + n = 6.60
• d + n = 80
  .10d + .05n = 6.60
• d + n = 80
  .05d + .10n = 6.60

Tags

CCSS.HSA.CED.A.3

At a college bookstore, Carla purchased a math textbook and a novel that cost a total of $54, not including tax. If the price of the math textbook, t, is $8 more than 3 times the price of the novel, n, which system of linear equations could be used to determine the price of each book?

• t + n = 54
  t = 3n + 8
• t + n = 54
  n = 3t + 8
• t + n = 54
  t = 3n - 8
• t + n = 8
  t = 3n + 54

Tags

CCSS.HSA.CED.A.3

Lisa and Tammy are selling items at the craft show.  Which might be a reasonable solution from the graph showing the number of items sold when they both have earned the same amount?

• (1, 12)
• (3, 19)
• (5, 25)
• (0, 10)

Tags

CCSS.8.EE.C.8B

The equations of two lines are 6x + y = 26 and y = 2x + 10. If the solution is (2, y), what is the value of y? 

• 14
• 4
• 6
• 2

Tags

CCSS.HSA.REI.C.6

David is running a concession stand at a soccer game. He sells nachos and sodas. Nachos cost $1.50 each and sodas cost $0.50 each. At the end of the game, David made a total of $78.50 and sold a total of 87 nachos and sodas combined. Which system of equations represents this situation?

• (35, 52)
• (18, 69)
• ( 52, 35) 
• (61, 26)

Tags

CCSS.8.EE.C.8C