Chapter 1
Chapter 1 Basic Math
Course: Ged Test Prep
Subject: Mathematics
Chapter: Chapter 4 Graphs And Functions
Proportional relationships occur when there is a constant ratio between two variables. In other words, as one variable changes, the other variable changes in proportion to it.
When two variables have a proportional relationship, their graph will always pass through the origin (0,0) and form a straight line that goes through the origin.
The equation of a proportional relationship takes the form y = kx, where k is the constant of proportionality. The constant k represents the ratio between the two variables.
In a proportional relationship, as x doubles, y doubles as well, and similarly, if x is cut in half, y is also cut in half.
Examples 1
Given the proportional relationship represented by the equation 𝑦=5𝑥, calculate the value of 𝑦 when 𝑥=4x.
Examples 2
If the graph of a proportional relationship passes through the point (6, 18), find the constant of proportionality 𝑘 and write the equation for this relationship.