Explanation for Question 15 From the Math (Calc) Section on the 2019 April Sat
For number 15, we want to know which of the following is a graph 2 of a system of equations with no solution. 3 And in order to do this one, you need to know what a solution 4 looks like on a graph. So if you have two lines graphed in a 5 coordinate plane, the solution of the system of equations, 6 it's going to be where they intersect. So we can see in B the 7 two lines intersect at this point here. 8 And that would be our one solution. 9 Then if we look at our other choices, we have two lines on top 10 of each other and see, so that means that there's going to be an 11 infinite number of solutions since they intersect at every point possible. 12 Then if we look at D we have two solutions here since 13 they intersect in two different places. 14 So that leaves a, a set of two parallel lines because 15 those two parallel lines are never going to touch. 16 So we are never going to have a solution.