1.9 - Direct Variation

​The table displays the distance a car travels, y, after x amount of hours.

​1.) What is the constant ratio? Is it proportional?

​2.) What is the rate of change? Or the slope?

​3.) What do you notice about our two answers?

​When two quantities have a constant ratio (unit rate) - their relationship is called a direct variation

​When two quantities vary directly, the graph will always go through the origin

​When writing equations, the direct variation, rate of change, slope, unit rate = k

​y = kx

​The form (y = kx)

​Find the unit rate, slope, rate of change and replace K with the value

​Example: A group bought tickets for an upcoming volleyball game. They bought 2 tickets for $15, 4 tickets for $30, and 7 tickets for $52.50. Is there a direct variation? If so, write an equation.