According to the Investopedia articles, all look to be Total assets - Total liabilities
. Then are they the same?
The book value of a company is the net difference between that company's total assets and total liabilities
Investopedia: Shareholder Equity (SE)
Shareholder equity (SE) is the owner's claim after subtracting total liabilities from total assets.
Investopedia: Debt-To-Equity Ratio (D/E)
Assets is $120,000 and liabilities is $100,000, so Ed's Equity is $20,000