Proportional Line Math Example 3

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

Example 3

easy
If y=4xy = 4x, find yy when x=7x = 7.

Solution

  1. 1
    Substitute: y=4(7)=28y = 4(7) = 28.
  2. 2
    In a proportional relationship, yy scales directly with xx.

Answer

y=28y = 28
In y=kxy = kx, doubling xx doubles yy. The relationship is a straight line through the origin.

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 1 easy

A recipe uses 3 cups of flour for every 2 cups of sugar. Write the relationship as [formula] and fin

Example 2 medium

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

Example 4 medium

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

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