What are the three practiced methods used for solving systems of equations?
Graphing Method, Substitution Method, and Elimination Method.
What does a system of linear equations, with no solution, look like?
Two Parallel Lines
To use the substitution method, what is the first step that needs to happen?
Solve one of the equations for a single variable (either variable will work)
What is the goal when using the Elimination Method?
To "eliminate" at least one of the variables when adding the equations together.
Find the slope of a line parallel to:
y=-5/2x-3
-5/2
Which method would be the fastest when solving this system of linear equations?
4x-3y=-2
2x-3y=6
The Elimination Method
What does a system of linear equations, with one solution, look like?
Two different lines with one intersection (aka two lines touching once)
Once one of the equations is solved for a single variable, what do you do with that solved equation?
Plug it in to the unsolved equation for the variable we solved for.
What would you do first to set up for elimination:
3x+8y=14
-6x+4y=-8
Multiply the top equation by 2
OR
Multiply the bottom equation by -2
Find the slope of a line perpendicular to:
y=-5/4x
4/5
Which method would be fastest to solve this system of linear equations?
y=-2x+3
y=-x
The Substitution Method
What does a system of linear equations, with infinitely many solutions, look like when graphed?
The same line twice (one on top of the other)
The solution of the following system of equations:
y=7x-11
y=6x-9
(2,3)
Show your work.
The solution of the following system of equations:
9x+8y=-25
-9x-8y=27
No Solution.
Show your work.
How do you know two equations are parallel?
They have the same slope and different y-intercepts.
In what method do you replace a variable with something of equal value?
The Substitution Method
What is the solution to this system of equations?
No Solution.
The solution of the following system of equations:
y=x+5
-3x+3y=-3
No Solution
Show your work.
The solution of the following system of equations:
-8x-3y=14
16x+5y=-26
(-1, -2)
Show your work.
How can you tell that two equations are perpendicular?
They have slopes that are opposites and reciprocals of each other.
What method are you using when you attempt to have one variable with the same number but opposite signs in a system?
The Elimination Method
What is the solution to this system of equations?
(1, -3)
The solution of the following system of equations:
x-7y=-3
2x-2y=6
(4, 1)
Show your work.
The solution of the following system of equations:
4x+6y=14
-3x+4y=15
(-1, 3)
Show your work.
How can you tell if two lines are perpendicular on a graph? (What is the definition of perpendicular?)
They meet at a 90 degree angle.