Read this page. Note that in one of the examples the trinomial cannot be factored. Then, try factoring trinomials yourself: click on the "new problem" button at the end of the page to try a practice problem. After answering the problem, click on the "check your answer" button. Continue this process by clicking on "new problem," and solve 10 problems. You can also create a worksheet of 10 problems by clicking on the button at the bottom of the page titled "Click Here for a Randomly Generated Worksheet and Answers." The answers will be provided at the end of the worksheet.