Graph y = - 1

Write the equation of a line that is perpendicular to y = -5x -8 and passes through the point (0,9)

Write the equation of a line that is parallel to y = and passes through the point (0,-6)

Chapter 8.9 system of linear equationsToday’s objectives:

- solve a system of linear equations through graphing and determine whether there is one solution, infinite solutions, or no solution.

Important vocabulary

• System of linear equations-two linear equations with the same two variables. The two

variables will make both equations true.ex: 2x -1 = y **the solution x = 5 and y = 9 makes x + 4 = y both statements true.

• Solution of a linear system- an ordered pair (x,y) whose values make both linear equations true.

We can graph two linear equations to find a solution…

Y = 2x – 4Y = -3x + 1

We can graph two linear equations to find a solution…

Y = x + 2Y = -2x + 2

We can graph two linear equations to find a solution…

Y = x + 4Y = 4x + 1

There can be 3 different outcomes to graphing a system of linear equations…

Find the solution to the system

y + 2x = 1y = -2x + 3

Find the solution to the system

y + x = 5y = -x + 5

Find the solution to the system

Y = x + 2Y = -x + 5

Steps we take to solve a system by graphing

1.) make sure both equations are in slope-intercept formy = mx + b

2.) graph both equations3.) find the solution

-three different outcomes1- one solution2- infinite solutions3 - no solution

Practice on your own

1.) y = – 3 2.) y – x = 5 3.) y + = 2 y = - + 1 y = x + 7 y – 2 =

Homework

Page 433 #’S 2-5, 7-21