Explanation for Question 4 From the Math (No Calc) Section on the 2018 March Sat
Question four says line L is shown in the X, 2 Y plane above line. M not shown is parallel to line L and 3 passes through the 0.03, which of the following is an equation of line 4 M. So the find the equation of a line we need to use the 5 Y equals MX plus B formula where M represents the slope and 6 Y represents the Y intercept. 7 And we just need to plug in the Y intercept and the slope. 8 And once we have that information, we'll know what the equation is for line 9 M. So first let's start with the Y intercept. 10 Well, we're told that the line passes through 0.03. 11 So we know that the Y intercept is three. 12 So our line should be, Y equals something times X plus 13 three. Next, we need to find the slope of the line. 14 Now we know it's parallel to line L, 15 which is shown on this graph. 16 And we also know that parallel lines have the same slope, 17 which means that we just need to find the slope of this line on 18 the graph. And that will be the same slope as line M slope. 19 So I'm going to do is just pick two coordinates here, 20 and I'm just gonna count the rise over run. 21 So this goes down to an over three. 22 So the rise is negative two because it goes down two and the run 23 is three. And so we know that the slope is negative two over three, 24 and that our lines equation should be Y equals negative two over three 25 X plus three. And so the answer.