Simplify the following text for a Grade 9 native English-speaking person.
Original: Upon the conclusion of the war , Jacka returned to Australia and entered business ; establishing the electrical goods importing and exporting business Roxburgh , Jacka & Co. .
Simplified: After the war , Jacka went back to Australia and started a business , Roxburgh , Jacka & Co. . Pty Ltd , importing and exporting electrical goods .