The soh mean when you want to find the sine of an angle you divide the opisite side by the hypotonus or o/h. The cah means when you want to find the cosine of an angle, you divide the adjasent line by the hypotonus or a/h. The toa means whe you want to find the tanjent of an angle, you divide the opisite line ny the adjecent line or o/a. Hope that helps with soh cah toa!
You would take the amount of increase and divide it by the amount of total cost over the time period of certain months. Then you would multiply that number by the percentage of increase gained, and subtract 96.12 to get your answer.