Remember that homework is a learning tool. Effective use of homework involves trying the problems yourself and using the solutions to help you learn - to confirm that you're on the right track and getting good results or to check for inspiration when there's a problem you don't know how to start. Finally, homework gives you the practice to make sure you can solve similar problems quickly, confidently, and accurately. Make sure to revisit problems as often as needed to gain that automaticity!
The assignment sheet identifies particular problems as either Core or Extension. I expect you to be able to work through similar problems to the Core problems independently by the time of the test. Redo Core problems (or ask for fresh ones!) until you can complete the work without referring to notes or solutions. Extension problems will likely require extra guidance or help at some point, and I expect you to understand how/why the solution works - you can test yourself on the concepts by asking how you might explain the posted answers.
The assignment sheet also lists the topics that most of the chapter 4 test will cover. Ideas from previous units will still appear (slope of a line, graph a given equation, combine like terms, etc.), but the bulk of the points will be earned through questions testing the concepts from the last part of chapter 4 (Systems of Equations and Inequalities). Check the assignment sheet to see if you can answer the questions listed under these two topics.