Question 348162
One approach to solving problems like this is to first graph the x- and y-inpute on a cartesian coordinate graph, that means use regular quadrille ruled graph paper.
When you do this carefully, you will notice that you have a straight line that crosses the y-axis at y=75 and it crosses the x-axis at x = 75.
From the graph, you can determine that the slope of the line is -1 because the line leans to the left (negative slope) and the slope (rise over run) is 75/75 = 1.
From this, you can write the equation of the line (the function) in the slope-intercept form: y = mx+b. where the slope is m = -1 and the y-intercept is b = 75. The function rule is:
{{{highlight(y = -x+75)}}} or, written as a function...
{{{highlight(f(x) = -x+75)}}}.
Here's what the graph should look like:
{{{graph(400,400,-5,85,-5,85,-x+75)}}}