Proportional Line Math Example 1

Follow the full solution, then compare it with the other examples linked below.

Example 1

easy
A recipe uses 3 cups of flour for every 2 cups of sugar. Write the relationship as y=kxy = kx and find kk.

Solution

  1. 1
    Let xx = cups of sugar, yy = cups of flour.
  2. 2
    The ratio is yx=32\frac{y}{x} = \frac{3}{2}, so k=32k = \frac{3}{2}.
  3. 3
    The proportional relationship is y=32xy = \frac{3}{2}x.

Answer

y=32xy = \frac{3}{2}x
A proportional relationship passes through the origin with equation y=kxy = kx. The constant kk is the ratio of yy to xx and is the slope of the line.

About Proportional Line

A straight line that passes through the origin, representing a proportional relationship of the form y=kxy = kx with constant ratio kk.

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More Proportional Line Examples

Example 2 medium

Does the table represent a proportional relationship? [formula]: 2, 4, 6; [formula]: 5, 10, 15.

Example 3 easy

If [formula], find [formula] when [formula].

Example 4 medium

Is [formula] a proportional relationship? Why or why not?

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