Please explain the correct approach for solving this financial accounting question.

A retail company purchased new display fixtures for $28,000. Old store equipment was sold for $2,500. A marketable security investment was sold for $45,000. Treasury stock was repurchased for $18,000, and dividends were paid to shareholders in the amount of $30,000. The company issued new bonds resulting in proceeds of $75,000. Calculate the net cash flow from investing activities.

Please provide the correct answer to this general accounting problem using valid calculations.