What’s the fastest way to do question 9 from practise test 2 section 3?
The fastest way might be to draw it. The first line goes through (1, 8) and has a slope of 2, which means it goes down 2 units and left 1 unit to (0, 6). The second line goes through (1, 2) and (2, 1), which means it has a slope of –1. Your drawing might look like this. (It’s OK that it’s ugly! You don’t need to draw it super carefully—just accurately enough to be able to trace the lines.)
From there, you can pretty easily use the slopes to trace the lines back to their intersection! The first line will go from (0, 6) to (–1, 4). The second line will go from (1, 2) to (0, 3) to (–1, 4). And there you have it—the intersection is (–1, 4)! Since the question asks for the sum of the coordinates, the answer is –1 + 4 = 3.