What is a the slope-intercept form of linear equation?
y=mx+b
14) What is the solution to the system of linear equations?

(2,2)
If we were to do substitution and have a graph of the same system of equations would we get the same solution?
Yes.
Every equation graphs a specific line so no matter how you solve, you get the same solution!
(Graphs are definitely easier, but we don't always have graphed systems!)
Solve the systems of equations using substitution:
y=3x-10
x=2
(2,-4)
True or False:
It does not matter which method you use when solving systems of linear equations because they will all give you the same answer.
True
What is the solution?

(-1,1)
What is the first step when solving a system of linear equations using the SUBSTITUTION method?
Get one of the variables by itself in one of the equations.
Solve the systems of equations using substitution:
y=2x-10
y=4x+8
(-9,-28)
What does it mean to "find the solution" to a system of linear equations?
It means to find the point where the two lines intersect (cross)
If the graph of a linear system of linear equations is two parallel lines, how many solutions are there? Explain.
There are no solutions because the two lines do not cross.
What is your new (one) equation after performing substitution?
y=2x
3x+y=20
3x+(2x)=20 or
5x=20
Solve the systems of equations using substitution:
y = -2x - 9
3x -6y = 9
(-3, -3)
What is a system of equations?
2 or more equations
Identify the slope and y-intercept of each of the equations.
Equation1: Slope is 1/4 and y-intercept is -2
Equation2: Slope is 3/2 and y-intercept is 3.
How would you isolate x in this equation?
6y+x=20
subtract 6x from both sides to get:
x=20-6x
Solve the systems of equations using substitution:
2x - y = 6
x = y + 5
(1, -4)
What are the 3 methods we use to solve systems of linear equations?
Graphing, Substitution, Elimination
To eliminate the "y", what must be done to the first equation and why?
2x - y = 4
x + 3y = 3
The first equation needs to be multiplied by 3 to have opposite coefficients.
Use the substitution method to solve the system of linear equations:
y=2x
3x+y=20
Solution: (4,8)
Use the Elimination method to solve the system of linear equations:
−8x − 10y = 24
6x + 5y = 2
(7,-8)