Explanation for Question 19 From the Math (Calc) Section on the 2019 May Sat
So question 19 asks for the linear function F the table above gives some 2 values of acts and their corresponding values of F of X, 3 where C is a constant, which of the following equations define F. 4 So if you look down here, you'll see that all of the answers are 5 in Y equals MX plus B form, 6 which tells us that what we're looking for is the slope, 7 which is M and the Y intercept, 8 which is B another equation that we're going to need here is this equation 9 I've written down on the bottle, Y two minus Y one over X, 10 two minus X one. And this formula is what we can use to find 11 the slope using two different points. 12 So, first let's find the Y intercept or the constant, 13 the beat of the equation. So to find the Y intercept, 14 all we have to do is go to where X equals zero, 15 which is right here on the chart and find the Y value. 16 So this tells us that the Y intercept of this graph is C. 17 So for that reason, we can eliminate B and D because they both have 18 three C as their Wiener step, which is incorrect. 19 And then after that, we can use the slope formula to plug in points 20 to figure out what the slope is. So let's just use two C minus 21 C over one minus zero. 22 And that tells us that the slope is C over one or C. 23 So now that we know that we know that C is the correct answer, 24 because it has C as the Y intercept and see as the slope.