Explanation for Question 12 From the Math (No Calc) Section on the 2018 March Sat
Question 12 asks, what is the solution set of the equation above. 2 Now we could, uh, try and simplify this equation to find what X equals, 3 but I think it would actually be faster to just plug in the values. 4 So we're going to start by just plugging in. So let's say we plug 5 in one to start. That would give us one minus two, 6 over one, minus three is equal to one over one, 7 plus one over one minus three. 8 And that simplifies to negative one over negative two, 9 which is just positive. One half is equal to one plus 10 one over negative two, which is negative one half. 11 And that becomes one half is equal to one half. 12 So we know that when we plug one into this equation, 13 both sides equal each other. And that means that one is a solution to 14 this problem. That means that B is incorrect because it doesn't have one as 15 one of the solutions. 16 Now let's plug in the next number let's plug into and see if that 17 works as well. So if we plug into, 18 we get to minus two, which is zero over two minus three, 19 which is negative one, which is just equal to zero is equal to one 20 over two, whoops, 21 one over two plus 22 one over two minus three, which is just negative one. 23 So that's just one half minus one, 24 which is not equal to zero. So we know that two is not a 25 solution to this problem and C is not the correct answer. 26 And then finally, let's just plug in three and see if that works. 27 If we plug in three to this equation, 28 we get three minus two, which is one over three minus three, 29 which is zero, which is undefined. 30 Um, and so we know that three, isn't an answer choice here. 31 And that means that the answer must be.