[Video] Q8: Which of the following equations represents a line that is parallel to the line with equation y = −3x+ 4 ?

Explanation for Question 8 From the Math (No Calc) Section on the Official Sat Practice Test 4

Now hearing number eight or asked, which of the following equations represents a line 2 that is parallel to this equation. 3 And so the background info that we need here is what does it mean 4 when lines are parallel? And I'm going to use these two lines, 5 uh, that's notation for saying that something is parallel is two parallel lines. 6 If lines are parallel, then they have to have two things. 7 They have to have the same slope and they have 8 to have different Y intercepts. 9 And that should make logical sense, right? Because if we have the same slope, 10 then there'll be going up at the same rate. So they'll never touch each 11 other. They'll always be going up right next to each other. 12 And if they have a different Y intercept, then that just means, 13 okay, they're not the same line because if they had the same slope and 14 the same Y intercept, they would just be two lines layered on top of 15 each other. 16 And so if we need to find a line that is parallel with what 17 we have here, then we need to look at each of these equations really 18 solve them so that they're in Y intercept form. 19 And then see if they have the same slope and a different y-intercept. 20 So we'll start with a, we've got six X plus two Ys equal to 21 15 to get the, 22 uh, the six X over. Right. 23 I want the Y on its own. So I'm going to subtract six X 24 from both sides so I can move the six X over and 25 then I need to divide by two. So I now get, 26 you know, cause I need the wide have no c...