Take note, for page 15 of the circle properties notes, change property 6's abbreviation to the one in the picture below. The numbers in the green boxes are important. Cancel property 7 as you can derive it from property 6. This is because cyclic quads are not in our syllabus. Also, you cannot use Alternate segment theorem as it is an A Math method, unless you are desperate. You can use it to check your answer though.
Now here, when you do questions which require you to equate 2 equations together and find the solution, make sure that once you find both x and y values, you pair them up, as shown below. Don't just leave them together.