Systems of Linear Equations

Alexandra finds that she can give 3 haircuts and 2 hair dyes in 315 minutes. Giving 2 haircuts and 4 hair dyes takes 450 minutes.  Which system of equations represents the situation?

• 3x + 2y = 315
  2x + 4y = 450

• 3x + 2y = 450
  2x + 4y = 315

• 2x + 2y = 315
  3x + 4y = 450

There are 50 donkeys and chickens on a far.  There are a total of 174 legs.  Which system below can be used to figure out how many of each animal the farm has?

• d + c = 174
  4d + 2c = 50

• d + c = 50
  4d + 2c = 174

• d + c = 50
  2d + 4c = 174

• d + c = 174
  2d + 4c = 50

This system has _____ solutions

• 0

• 1

• 2

• Infinitely many

At a restaurant the cost for a breakfast taco and a small glass of milk is $2.10. The cost for 2 tacos and 3 small glasses of milk is $5.15. If a system of equations is written, which would be the correct representation of the 2 variables?

• t: # of tacos

  m: # of glasses of milk

• t: Cost of each taco

  m: Cost of each glass of milk

• t: total cost

  m: # of food items

• t: Cost of each glass of milk

  m: Cost of each taco

How many solutions will this system have? 

• No solution

• One Solution

• I Don't Know

• Infinitely Many Solutions

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

• (-4, 2)

• (4, 2)

• (2, -4)

• (2, 4)

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

• (1, -2)

• (-2, 1)

• (-4, 1)

• (2, 1)

Solve for x and y using any method we've learned!
y = 2x + 1
y = 4x - 1

• (1,3)

• (-1,-3)

• (-1,3)

• (3,1)

Solve the system of equations below:
9x - 4y = 1
-3x + 8y = -47

• (3, -7)

• (-3, 7)

• (-3, -7)

• (-7, -3)

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

• (-7,0)

• (6,0)

• (-6,0)

• (7,0)