Explanation for Question 5 From the Math (Calc) Section on the 2017 May Sat
Question five says for each repair job and elevated technician charges are dollars 2 per hour for each hour worked plus a flat fee of K dollars. 3 If a technician charges 210 for a two hour job, 4 which of the following represents the relationship between R and K based 5 on these answer choices. And when we just read, 6 we know that we have to create an equation and Y equals MX plus 7 B form. Um, 8 always sources have one thing in common and it's that we have a 210 9 equals something. That's just because 210 is what they tell 10 us is what he charges, which is what the whole line we're creating should 11 equal two. So now we just have to find out what the MX and 12 B are. The B is going to be the easiest thing to find out 13 here. B is our Y intercept in the Y equals MX plus B format. 14 It's essentially just like where we're starting. 15 If you think about it in the sense of a line is where the 16 line crosses the white, um, white Oxys, 17 but in the sense of a real world scenario, 18 um, it's just where we start or our baseline. 19 So in this case, it's going to be the flat fee that he charges. 20 So no matter what we know that that's been charged, 21 and if we read here, the flat fee is K. 22 So we're going to have a K here, um, 23 that already knocks out a lot of our answers. 24 We can cross out B and C. 25 Um, now the last thing that we're missing is that MX, 26 so the slope, um, and the hour. 27 So it says an elevated take this in charges are dollars per hour, 28 and it's a two hour job. So for one hour, 29 he charges are for two hours. He charges two are so that we're going 30 to have that right there. Now none of our answer choices looks exactly like 31 this, but we're adding these. So these can be flipped without changing any value. 32 So we're left with two, 10 plus two 10 equals K plus two 33 R or a.