FINDING THE EQUATION OF A LINEAR RELATIONSHIP. We can use the points on a graph of a linear relationship to write an equation for the relationship. The equation of a linear relationship is y = mx + b, where m is the rate of change, or slope, and b is the y-intercept (The value of y when x is 0). Example 1 : A handrail runs alongside a stairway. As the horizontal distance from the bottom of the stairway changes, the height of the handrail changes.
Ans: The equation that represents a proportional relationship, or a line, is y=kx, where k is the constant of proportionality. Use k=yx from either a table or a graph to find k and create the equation. Proportional relationships can be represented by tables, graphs and equations.
