Explanation for Question 5 From the Math (Calc) Section on the 2019 March Sat
Uh, question five says lines L and K in the X, 2 Y plane above are the graphs of the equations in a system. 3 How many solutions does the system of equations have? 4 So when a system of equations has a solution, 5 that just means that the two equations intersect. 6 So this question is basically asking how many times do these two lines intersect? 7 And if you look at the graph, there's only actually one intersection right there. 8 Now we know that there can't be a second intersection because lines with different 9 slopes can only intersect once or less. 10 The only time that they intersect more than once is if they're the same 11 exact line, in which case there's an infinite number of intersections 12 and an infinite number of solutions. But in this case, 13 that's clearly not the case. We can see two different lines. 14 And so we know that the, it only intersects once. 15 So the answer here is B.