Exploring Direct Variation in 8th Grade Math

This video tutorial covers the concept of direct variation, which is a type of proportional relationship. It explains how to find the constant of variation, k, using the formula y = kx, where k is the slope. The tutorial demonstrates solving direct variation problems using both equations and proportions, and applies these concepts to real-world scenarios such as calculating water usage and hotel costs.

What is another name for a direct variation relationship?

• Non-proportional relationship

• Linear relationship

• Inverse relationship

• Proportional relationship

In the direct variation equation y = kx, what does k represent?

• The y-intercept

• The constant of variation

• The x-intercept

• The dependent variable

If y = 18 and x = 3, what is the value of k in the direct variation equation?

• 12

• 9

• 6

• 3

Given y = 10 and x = -50, what is the direct variation equation?

• y = 5 x

• y = -5 x

• y = 1/5 x

• y = -1/5 x

How do you find the constant of variation (k) using a proportion?

• By adding y and x

• By subtracting y from x

• By dividing y by x

• By multiplying y and x

If y = 75 when x = 15, what is the value of x when y = 100?

• 20

• 15

• 25

• 10

A dishwasher uses 36 gallons of water for 12 loads. How many gallons will it use for 10 loads?

• 28

• 30

• 32

• 34

Meredith can make 5 bracelets in 2.5 hours. How many bracelets can she make in 6 hours?

• 10

• 12

• 14

• 16

If a customer pays $384 for 4 nights at a hotel, how much will they pay for 5 nights?

• $470

• $480

• $450

• $460

What is the method used to solve real-world direct variation problems in this tutorial?

• Using proportions

• Using equations

• Using graphs

• Using tables