I need help creating some type of formula that will help me in solving thesse types of problems?

At the beginning of the year, Monty Company had total assets of $819,000 and total liabilities of $442,000. Answer the following questions.

(a) If total assets increased $164,000 during the year and total liabilities decreased $64,000, what is the amount of stockholders’ equity at the end of the year?

Stockholders’ equity

$

(b) During the year, total liabilities increased $112,000 and stockholders’ equity decreased $61,000. What is the amount of total assets at the end of the year?

Total assets

$

(c) If total assets decreased $54,000 and and owner’s equity increased $105,000 during the year, what is the amount of total liabilities at the end of the year?

Total liabilities