10/17 Show Me What You Know!

What is the best method to use?

2x − 3y = −1

y =x − 1

• Graphing

• Substitution because a variable is defined

• Elimination because the equations are in standard form.

What is the best method to use?

−4x − 2y = −12

4x + 8y = −24

• Graphing

• Substitution because a variable is defined

• Elimination because there is already a variable that would cancel out.

Solve the system of linear equations

• (5, -2)
• Infinite solutions
• (-2, 5)
• no solutions

Steffen graphed two lines in order to find the solution to a given system of equations.
What is the solution?

• (-3,-8)
• (-8,-3)
• (3,-8)
• (8,3)

The first step in solving using the substitution method is __________.

• get x by itself

• get y by itself

• get either variable by itself

• add the equations together

Solve for x and y
5x + 3y = 7
y = 4

• (4,1)
• (4,-1)
• (1,4)
• (-1,4)

Solve the system by substitution. 
3x − 2y = 7 
y = 2x − 7 

• No solution 
•  (7, 7)  
•  (−7, −7)  
•  (−7, −3)  

What are ALL the possible solutions to a System of Equations?

• One Solution

• Infinite Solutions

• No Solution

• Two Solutions

Solve:
8x + 4y = 12
y = -2x + 3

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

Solve the system of linear equations

• (0, 3)
• Infinite solutions
• (0, 0)
• no solutions