Solving Systems Using Substitution and Elimination

Solve the following systems of equations using substitution:

2y + x = -15

x = 3y

• (-3, -9)

• (-9, -3)

• (-3, 9)

• (9, -3)

What is the best method to use?

−4x − 2y = −12

4x + 8y = −24

• 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

The talent show committee sold a total of 530 tickets in advance. Student tickets cost $3 each and the adult tickets cost $4 each. If the total receipts were $1740, how many of each type of ticket were sold?

• S + A = 530
  3S + 4A = 1740

• S + A = 530
  4S + 3A = 1740

• S + A = 1740
  3S + 4A = 530

• S + A = 1740
  4S + 3A = 530

Solve the system:
3x + y = 19
2x - y = 6

• (5, 14)

• (4, 5)

• (5, 4)

• (14, 5)

Which method would be best (quickest) for solving the system below:
x + y = 11
3x - 4y = -2

• Substitution

• Elimination

• Graphing

• None of these

Solve the system:
x + y = 19
y = 3x - 1

• (14, 5)

• (11, 8)

• (5, 14)

• (8, 11)

Which method would be best (quickest) for solving the system below:
3x - 4y = -2
y = 2x + 1

• Substitution

• Elimination

• Graphing

• None

Solve the system:
x + 6y = 17
x - 3y = 8

• (5, 2)

• (11, 1)

• (1, 11)

• no solution

Solve by elimination:

7x+y=-9

-3x-y=5

• No solution

• (1,8)

• (-1,-3)

• (-1,-2)