Solving Systems of Linear Equalities

Solve:
x + y = 4
-5x - 6y = -18

• (6, -2)

• (-6, 10)

• (2, 2)

• (-2, 6)

Solve:
-2x + 5y = -1
4x - 2y = -6

• (-2, -1)

• (2, 7)

• (3, 1)

• (-1, -2)

What is the solution?

• (1, -1)

• (-1, 1)

• (0, -2)

• (2, 0)

What is the solution?

• One Solution

• No solution

• Infinitely Many Solutions

The cost of 5 squash and 2 zucchini is $1.32. Three squash and 1 zucchini cost $0.75. Write a system of equations.

• 5q + 2z = 1.32
  1z = 0.75

• 5q + 2z = 1.32
  3q + 1z = 0.75

• q + z = 1.32
  q + z = 0.75

• 5q + 2z = 0.75
  3q + 1z = 1.32

Homer sells tickets for admission to your school play and collects a total of $104. Admission prices are $6 for adults and $4 for children. He sold 21 tickets total. Write a system to represent this situation assuming "a" represents # of adult tickets and "c" represents # of children's tickets.

• a + c = 21
  6a + 4c = 104

• a + c = 104
  6a + 4c = 21

• a + c = 21
  6c + 4a = 104

• a + c = 104
  6c + 4a = 21

On Monday Joe bought 10 cups of coffee and 5 doughnuts for his office at the cost of $16.50.  On Tuesday he bought 5 cups of coffee and 10 doughnuts for a total of $14.25. Which equations could be used to determine the cost of the coffee? 

• 10c + 5d = 14.25
  5c + 10d = 16.50

• 10c + 5d = 16.50
  5c + 10d = 14.25

• c + d = 10
  5c + 10d = 16.50

• c + d = 5
  5c + 10d = 16.50

Your family goes to a restaurant for dinner. There are 6 people in your family. Some order the chicken dinner for $14.80, and some order steak for $17. If the total bill was $91, which system best represents the situation? 

• x + y = 6
  14.80x + 17y = 91

• x + y = 91
  14.80x + 17y = 6

• x + y = 6
  14.80y + 17x = 91

• x + y = 91
  14.80x+ 17y = 6

Flagship Cinemas sells movie tickets that are $4 for matinees and $7 for regular. One night, the theater sells 578 tickets and collects $3365 in total ticket sales.
Which system best represents the situation?

• 4x + 7y = 578
  x + y = 3365

• 4x + 7y = 3365
  x + y = 578

• 4y + 7x = 578
  x + y = 3365

• 4y + 7x = 3365
  x + y = 578

Using elimination or substitution, what is the solution to the following equations?

• (3, -2)

• (2, -3)

• (-3, -2)

• (-2, 3)