Edit and correct the formula used for a web-based calculator

Edit and correct the formula used for a web-based calculator for income projection at [login to view URL] . The formulas applied in this calculator are not the correct formulas that I gave. Hence the results of using the calculator are wrong answers. The second issue to be resolved is the generation of the PDF of the result in the admin section. The admin has been created, and a PDF is supposed to be generated for the results of using the calculation. But there seems to be an error that the first developer has not resolved. How quickly can you correct these issues?