Evauate 15 divide by r minus 1 when r = 5

2/5 or .4

Step-by-step explanation:

basically look at the points where the line meets the graph. two points would be 0,20 and 50,40. then count the amount that it changes vertically and then horizontally. +20vertical +50 horizonal giving the slope 20/50. this can then be simplified to 2/5 or the equivalent number .4