Slope-Intercept Form
Find the slope between the two points.
(16,1) (17,7)
6
Write an equation of a line that passes through the point (-2, -3) and has a slope of -1/3.
y+3 = -1/3 (x+2)
Rewrite the following equation in standard form.
y = 1/3 x -2
x -3y = 6
Suppose you receive $100 for a graduation present, and you deposit it in a savings account. Then each week thereafter, you add $5 to the account but no interest is earned.
Write an equation to model the situation.
y=100+5x
study hours 3 2 5 1 0 4 3
grade 84 77 92 70 60 90 75
positive correlation
Write the equation for the line in slope-intercept form.
5y+10x=-2x
y= -2/5 x -2
Write the equation of a line in point slope form given the following information.
Slope: -4 y-intercept: -4
y+4 = -4(x+0)
Rewrite the following in standard form.
y - 2 = 3/4 (x +4)
3x-4y=-20
Nick is given $50 to spend on a vacation . He decides to spend $5 a day. The amount Nick has left and the number of days are related.
Write an equation to model the situation. How much money will Nick have left after 3 days?
$35
child's age 3 6 9 12 15
annual cost 10,700 11,700 12,600 15,000 16,700
r = 0.9825
Strong positive correlation
Find the slope and y-intercept of the following equation.
6 - 2y = -x
slope: 1/2
y-intercept: (0, 3)
A line has a slope of 1/2. Through which 2 points could the line pass?
a. (5, 8), (6,10)
b. (-3, 6), (-5, 5)
c. (4, 5), (1, -6)
b. (-3,6), (-5,5)
Write the equation of the line in all THREE forms.
y-intercept: -4 slope: 2
y = 2x - 4
y+4 = 2(x-0)
2x-y=4
In 1995, Orlando, Florida, was about 175,000. At that time, the population was growing at a rate of about 2000 per year.
Write an equation, in slope-intercept form to find Orlando’s population for any year. In what year will the population be 250,000.
y=175,000+2000x
During 2032 (37.5 years later)
Write an equation for the line of best fit for the following data.
height 67 70 73.5 75 78 66
shoe size 8.5 9.5 11 12 13 8
Use your equation to predict the shoe size of a person that is 85 inches tall.
y=0.421132x - 19.8127
Shoe Size: around size 16
y - 1 = 3/5 (x - 2)
y=3/5 x - 1/5
Write the equation of the line that passes through the two points in point slope form.
(1, -2) (3, 5)
y+2 = 7/2(x-1)
or
y-5 = 7/2(x-3)
Identify the x-intercept, y-intercept, and slope of the following equation.
3x+4y=12
x-intercept: (4,0)
y-intercept: (0,3)
slope: -3/4
Suppose a 5-minute overseas call costs $5.91 and a 10-minute call costs $10.86. The cost of the call and the length of the call are related.
Write an equation to model the situation using point slope form.
y-5.91 = 0.198(x - 5)
or
y-10.86 = 0.198(x-10)
If a set of data had a correlation coefficient of -0.12, what could you say about the data?
Data has no correlation. Correlation coefficient is close to 0.
Identify the slopes of the two lines below.
Line A: x = -3
Line B: y = 6
Line A Slope: Undefined
Line B Slope: 0
Rewrite the following equation in point-slope form.
y = 1/2 x -4
y +4 = 1/2 (x-0)
Fill in the blank to create an equation in standard form that will have a slope of 1/2 and have a y-intercept of -2.
x- _____ y=4
2
A construction company charges $15 per hour for debris removal, plus a one-time fee for the use of a trash dumpster. The total fee for 9 hours of service is $195.
Write an equation of a line, in slope-intercept form, to find the total fee y for any number of hours x.
y=15x+60
The data below shows the weight of an alligator over time measured in weeks.
weeks 0 9 18 27 34 43 49
weight 6 8.6 10 13.6 15 17.2 19.8
How old would an alligator be that weighed 24.6 lbs?
about 68 weeks