Let x be the number of years that have passed since 1900 (at 1900, x = 0). Let y be the total meters of erosion. Write an equation in terms of x and y to represent the erosion at any point between 1900 and 1905.

y = x

Explanation:

Looking at the graph, we can retrieve two coordinates from the range we are given: (0, 0) and (5, 5). Because 1900 is the starting x-coordinate of the graph, we can represent it at 0.

You can find the slope of this equation using this formula:

Your slope is equal to 5/5, or 1.

Because the function's y-intercept is equal to 0, there is no need to add anything to the function.