Solving Linear Systems

What is the solution to this system of equations?

• (4, -1)
• (-1, 4)
• (-4, 1)
• (-4, -1)

What are systems of linear equations?

• a set of two or more linear equations in the same variables
• a polynomial with three terms
• set of two or more linear inequalities in the same variables

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is a solution of a linear system?

• the slope of the line
• the y-intercept
• the point where the systems intersect
• the rise over tun

Graph both equations. What point do they intersect at?
x = 5
y = -2/5x + 1

• (5, -1)
• (-1,5)
• (5, -3)
• (5, -24)

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

• (-4, 2)
• (4, 2)
• (2, -4)
• (2, 4)

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

Solve the system using substitution.
y = 6x - 5
6x - 7y = -1

• (1,1)
• (-1, -11)
• No Solution
• Infinitely many solutions

Solve the system using substitution.
-7y + 5x = -3
x = 5y - 15

• (5,4)
• (4,5)
• No Solution
• Infinitely Many Solutions

Solve the system by elimination.  

−8x − 10y = 20
−8x − 6y = −4 

• (-5, -6) 
• (6, 5) 
• (−6, −5) 
• (5, −6) 

Solve the system of equations by multiplication.
y = 8x + 12
-5x +4y = 21

• (1, -4)
• (1, 20)
• (-1, 20)
• (-1, 4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6