(25) GCSE Maths - How to Write Algebraic Expressions for Directly Proportional Relationships #90

In directly proportional relationships, we express the relationship between two variables, such as x and y, using the equation y = kx, where k is the constant of proportionality. This means that as x increases, y increases at a constant rate, allowing us to easily calculate one variable if we know the other. To write an algebraic expression for a directly proportional relationship, we start by identifying the variables involved and determining the value of k through given data points. Once we have the value of k, we can substitute it back into the equation to obtain the specific expression that describes the relationship between x and y.