Pre Calc Chapter 2

If a system of equations has no solution, what does the graph look like? 

• intersecting lines
• parallel lines
• skew lines
• intersecting lines

Does the system have one, none or infinite solutions?
8x + 4y = 12
y = -2x + 3

• (0,3)
• (3,0)
• No solution(parallel lines)
• Infinitely many solutions

Solve using substitution.
x - 2y = 2
3x + 4y = 3

• (1.4, -0.3)
• (3.1, 5)
• (-2.5, 3.5)
• (6.9, 1.02)

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?

• 1.5x+0.5y=78.5
  x+y=87
• 1.5x+0.5y=78.5
  1.5x+0.5y=87
• x+y=78.5
  1.5x+0.5y=87
• x+y=78.5
  x+y=87

CHALLENGE: Three equations.
x + y + z = 4
x = -2y
z = -3y
Solve the system of equations using substitution.

• y = -1
  x = 2
  z = 3
• y = 3
  x = -5
  z = 1
• y = -2
  x = 10
  z = 0
• y = 1
  x = 4
  z = -1