Can you use slope intercept form?
Section 4.7
• What do you know about slope-intercept form?
• Break down the phrase….
• A linear equation y = mx+b is written in slope-intercept form;
where m is the slope and
b is the y-intercept.
Slope – Intercept form…
-2x + y = -3
Find the slope and y-intercept…
First thing we do…
Get it into slope-intercept form.. y =
mx + bSecond thing we do… Pick out the
slope and the y-intercept
Y = 2x - 3 ? ?
Slope: 2 Y- intercept: -3
(1) Find the slope and y-intercept
(2)Plot the point (0,b) ; when b = -3(3) Use the slope to locate a second point on the line.
(4)Draw a line through the two points
3x + 4y = 8
What about this…
SLOPE?
Y-intercept?
7y – 14x = 28
You Try it…
What does it mean to be parallel?
• .
Parallel Lines…
Parallel bars?Parallel
parking?
• Parallel lines are DIFFERENT lines in the same plane that never intersect. If they have
the SAME SLOPE and different y-intercepts, they
are deemed as parallel.
• Any two vertical lines are parallel
The REAL Definition..
Line A: 3y = -9x – 5 Line B: 2y – 6x = -5 Line C: 12x + 4y = 1
How can you tell which lines are parallel…
(1) Rewrite each equation in slope-intercept form…
(2) Identify the slope of each equation (3) Compare the slopes;
• If they are have the same slope, then they are parallel..
Page 246#1,2,11-29(odd),49,
51, 53(15 problems)
Homework
Grab a board, a marker, and
an eraser
Get with a partner…
What is the equation for slope-intercept form…..
Find the slope and y-intercept of the
equation…
y = 2x + 1
Find the slope and y-intercept of the
equation…
y – x = 3
Rewrite the equation in slope-intercept form…
3x + y = -11
Rewrite the equation in slope intercept form…
3x – 6y = 18
Find the slope and y-intercept of this
equation….
3x + 4y = 16
Find the slope and y-intercept of this
equation….
X + y = 0
Determine if the two equations are parallel
lines…
line a: 2x – 12 = y
line b: y = 10 + 2x
What’s your wager?!?!
Challenge Question….
Determine which graphs of the equations are parallel lines….
LINE A: 3y – 4x = 3
LINE B: 3y = -4x + 9
LINE C: 16x -12y = 24