Equivalent Ratios
Write a ratio that is equivalent to 3:5.
6:10 ect.
Is this proportional?
x: 1, 2, 3, 4
y: 5, 10, 15, 20
Yes
Find k if y=7x.
7
Complete the equation for a proportional relationship with k=6.
y = 6x
Movie tickets cost $8 each. Write an equation for total cost y for x tickets.
y = 8x
Write a ratio that is equivalent to 4:7.
ect.
Is this proportional?
x: 2, 4, 6, 8
y: 7, 14, 21, 29
Find the constant of proportionality:
x=4, y=18
k = 4.5
For y=5x, what ordered pair occurs when x=7?
(7,35)
A gym charges $12 per class plus a one-time $25 registration fee. Write the equation.
y = 12x + 25
The ratio of red marbles to total marbles is 2:5. If there are 35 marbles total, how many are red?
14 Red Marbles
Which equation represents a proportional relationship?
A) y=4x B) y=4x+2 C) y=x+4 D) y=4
A
Find k:
Hours: 2, 3, 5
Miles: 16, 24, 40
k = 8
A table shows Hours: 1.5, 2.5, 3.5 and Miles: 12, 20, 28. Write the equation.
y = 8x
Used games cost $15 each and a controller costs $50. Write the total-cost equation for x games.
y = 15x + 50
A recipe uses 6 cups of water for 4 cups of rice. How many cups of water are needed for 10 cups of rice?
15 cups
A table has points (3,12), (5,20), (7,28), (9,36). Is it proportional? Explain.
Yes; y/x = 4 for every pair
A machine makes 54 parts in 6 minutes. What is the constant of proportionality in parts per minute?
9
A bird flies 14 miles per hour. Give the distance after 3.5 hours.
49 miles
A taxi charges a $4 starting fee plus $2.50 per mile. Write the equation for x miles.
y = 2.5x + 4
A cyclist travels 9 miles in 1.5 hours. At the same rate, how long will 30 miles take?
5 hours
A graph is a straight line but crosses the y-axis at 3. Is it proportional? Why or why not?
No; a proportional graph must pass through (0,0)
If y is proportional to x and (2.5, 17.5) is on the graph, write the equation.
y = 7x
A proportional graph contains (0,0), (2,18), and (4,36). State k and the equation.
k = 9; y = 9x
A phone plan costs $35 each month plus $8 per GB of data. Write the equation and find the cost for 6 GB.
y = 8x + 35; $83