How do you write a relationship using letters?

To write a relationship using letters, use variables to represent quantities and express their connection through an equation.

In mathematics, relationships between quantities are often represented using variables, which are typically letters like \( x \), \( y \), or \( z \). These variables stand in for numbers and allow us to create general rules or formulas. For example, if you have a relationship where the total cost \( C \) is equal to the number of items \( n \) multiplied by the price per item \( p \), you can write this as \( C = n \times p \).

Using letters to represent relationships helps simplify complex problems and makes it easier to manipulate and solve equations. For instance, in physics, the relationship between distance \( d \), speed \( s \), and time \( t \) is often written as \( d = s \times t \). This equation tells us that distance is the product of speed and time.

In algebra, you might encounter linear relationships, which can be written in the form \( y = mx + c \), where \( y \) and \( x \) are variables, \( m \) is the slope of the line, and \( c \) is the y-intercept. This equation describes a straight line on a graph and helps us understand how changes in \( x \) affect \( y \).

By using letters to represent quantities, we can generalise mathematical concepts and apply them to a wide range of problems, making it a powerful tool in both pure and applied mathematics.