Complete the following equations:

a$.$ Assets of $$40,000=$ Liabilities of $$17,200+$ Owner's Equity of $

b$.$ Assets of $ $-$ Liabilities of $$18,000=$ Owner's Equity of $$22,000$

c$.$ Assets of $$27,000-$ Owner's Equity of $$15,000=$ Liabilities of $ $$