Key Words
The phrase “per hour” tells you what in slope-intercept form?
The slope
A gym charges a $25 sign up fee and $15 per month. What is the slope?
15
A gym charges a $25 sign up fee and $15 per month. What is the y-intercept?
25
A babysitter charges $10 per hour and no starting fee.
y = 10x
y = 5x + 10
Find y when x = 4
y = 30
The phrase “starting with” tells you what?
The y-intercept
A babysitter earns $12 per hour. What is the slope?
12
A savings account starts with $200 and increases by $10 per week. What is the y-intercept?
200
A streaming service costs $12 per month plus a $5 sign up fee.
y = 12x + 5
y = 3x + 8
Find y when x = 6.
y = 26
The phrase “decreases by 7 each week” tells you what about the slope?
The slope is negative 7
A taxi charges $3 to get in and $2.50 per mile. What is the slope?
2.50
A taxi charges $3 to get in and $2.50 per mile. What is the y-intercept?
3
You start with $80 and SPEND $6 per week.
y = -6x + 80
y = -2x + 15
Find y when x = 5.
y = 5
The phrase “flat fee”, "start-up", or "initiation fee" tells you what part of the equation?
The y-intercept
A savings account starts with $100 and increases by $20 each week. What is the slope?
20
A car rental company charges $50 flat fee plus $30 per day. What is the y-intercept?
50
A taxi charges $4 to start and $3 per mile.
y = 3x + 4
A taxi charges $4 to start and $3 per mile.
Write the equation and find the total cost for 7 miles.
y = 25
The phrase “for every mile” represents what? (slope or y-intercept)
It represents the slope
A phone battery starts at 90% and decreases by 5% every hour. What is the slope?
-5
A student starts with $40 and spends $8 per day. What is the y-intercept?
A tank starts with 100 gallons and drains 8 gallons per hour.
y = -8x + 100
A water tank starts with 100 gallons and drains 8 gallons per hour.
Write the equation and find how much water is left after 6 hours.
y = 52