Slope- Intercept Form
What is the slope?
y=-4x+0.5
m= -4
What is the formula for point-slope form?
y- y1= m (x- x1)
What is the formula for standard form?
Ax + By = C
Parallel lines have ____________ slope.
The same slope.
Write
y- 100= -50 (x-3) in standard form.
50x+ y =250
What is the y-intercept?
y=2.5x - 1.5
b= -1.5
What is the slope of the equation:
y + 11 = 7(x + 4)
m=7
Jake needs to buy 140 beverages for a party. What equation, in standard form, determines the numbers of 7-packs of juice x and 12-packs of water y that Jake can buy?
___x + ___y =_____
7x + 12y = 140
Perpendicular lines have _________________.
opposite and reciprocal slopes
Ex: m1= 2 m2= -1/2
Lance is reading a biography for his history class. He reads 30 pages each day. After 9 days, Lance has read 3/5 of the biography. This scenario is modeled by the equation below.
y= -30x +450
What does the
y-intercept represent?
A pages already read
B pages in the book
C pages read each day
D days it takes to finish the book
B pages in the book
Do you graph the slope or y-intercept first?
Y-intercept
Byron jogs home from a park at an average speed of 6 mi/h. After half an hour he is 4 miles from home. What is an equation, in point-slope form, that represents Byron’s distance from home, y, after x hours?
A y-4= -6 (x- 0.5)
B y-6= -4 (x- 0.5)
C y+4= -6 (x- 0.5)
D y-4= -6 (x+ 0.5)
A y-4= -6 (x- 0.5)
What are the x- and y-intercepts of the graph of:
9x + 6y = 30?
x-intercept: (10/3, 0)
y-intercept: (0, 5)
Select all the equations that represent lines that are perpendicular to the graph of
3x + 18y = 5.
A y = 3x − 10
B x = 3
C y + 1 = 6(x − 15)
D -6x + y = 8
E 2x − 3y = 5
C and D
Andre is riding home from a friend's house. After 5 minutes he is 4 miles from home. After 15 minutes he is 2 miles from home. Which equation models Ye’s distance from home, y, in terms of minutes, x?
A y = 5x − 0.2 C y = 0.2x
B y= -0.2x -5 D y = −0.2x + 5
D. y = −0.2x + 5
Re-write the equation in slope-intercept form:
4x + 8y = 16
y= -1/2x +2
Ben puts $5 in his account every day. If he has $22 after 4 days, what is an equation of the line in point-
slope form?
A y − 22 = 5(x + 4)
B y + 1 = −5(x + 2)
C y − 22 = −4(x − 5)
D y - 22 = 5(x -4)
D: y - 22 = 5(x -4)
Jake needs to buy 140 beverages for a party. Below is the equation modeling the numbers of 7-packs of juice x and 12-packs of water y that Jake can buy.
7x +12y = 140
Select all the ordered pairs that represent combinations of packs of juice and packs of water that Jake can buy.
A (20,0)
B (20/7, 10)
C (0, 11.667)
D (30, −10)
A
What is the equation in
slope-intercept form of the line that passes through the point (−1/3,5 ) and is parallel to the graph of
y = −9x − 2?
y = ___x +____
y= -9x +2
Set Up:
y- 5= -9(x +1/3)
y-5 =-9x -3
y= -9x +2
Bonus Points!
The team who chose it gets 400 points.
The other teams get 200 points.
Bonus Points!
The team who chose it gets 400 points.
The other teams get 200 points.
Lexi is reading a biography for her history class. She reads 20 pages each day. After 4 days, Lourdes has read 1/4 of the biography. Write a linear equation to represent the number of pages Lexi still has to read after
x days.
y =__x +___
y= -20x +320
An elevator rises steadily up a skyscraper. After 4 s it is 33 m above the ground. Two seconds later it is 47 m above the ground. Which equation models its height, y, with respect to time, x?
A y − 33 = −7(x − 4)
B y − 47 = −7(x − 2)
C y − 33 = 7(x − 4)
D y + 33 = 7(x + 4)
C y − 33 = 7(x − 4)
A flashlight shines horizontally across a lake from a height of 5 ft above a bridge (the origin on the coordinate plane). For which values of A, B, and C will Ax + By = C represent the line on which the beam of light lies, where x is the horizontal distance and y is the vertical distance, in feet, from
the bridge?
A = __, B = __, C = __
A=0 B=1 C=5
AB of rectangle ABCD passes through the point (2, 0) and is perpendicular to the graph of y=-1/3x-7. CD is parallel to AB and passes through point (−1, 6). Select the equation in slope-intercept form of the line that includes .
A y= -1/3x +9
B y=3x +9
C y = −3x + 9
D y = 3x -3
B
What is slope-intercept form?
y= mx +b