Systems of Equations Which to Use

Solve the following systems of equations using substitution:

y = 3 - x

3y + x = 5

• No solution

• (1, 2)

• (3, 0)

• (2, 1)

Solve the following systems of equations using substitution:

y = 8

y = -4x + 4

• (8, -1)

• (-28, 8)

• (-1, 8)

• (8, -28)

Solve the following systems of equations using substitution:

x = 6

y = 2x - 3

• (6, 6)

• (6, 9)

• (9, 6)

• (9, 9)

How many solutions does the graph have?

• One solution

• No solution

• Infinite solutions

Solve:
y=8x+1
y=6x+3

• (1, 9)

• (4, 14)

• (0, 1)

• (2, 4)

Solve the following system by graphing.  What is the solution?

• Infinite number of solutions

• (3, 3)

• (3, -3)

• (-3, 3)

A large pizza at Palanzio’s Pizzeria costs $6.80 plus $0.90 for each topping. The cost of a large cheese pizza at Guido’s Pizza is $7.30 plus $0.65 for each topping. Which system of equations could be used to find the number of toppings when both companies cost the same amount?

• y = 6.80 + .65x
  y=7.30+.90x

• x + y = 6.80
  x + y = 7.30

• y = 6.80+.90x
  y = 7.30 + .65x

• y + .90x = 6.80
  y + .65x = 7.30

Solve by elimination:
4x+9y=28
-4x-y=-28

• (-7,0)

• (6,0)

• (-6,0)

• (7,0)

Solve by elimination:
7x+y=-9

-3x-y=5

• No solution

• (1,8)

• (-2,-3)

• (-1,-2)

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

• (5, 2)

• (11, 1)

• (1, 11)

• no solution