Explanation for Question 16 From the Math (No Calc) Section on the Official Sat Practice Test 3
So for number 16, we are given this equation here, 2 right? And we want to solve for X we're asked for a possible solution, 3 which means we're solving for X. And so essentially whenever you want to solve 4 for X, you really want to simplify as well. 5 We can start simplifying by distributing out that X to the third. 6 We get X to the fifth minus five X. 7 The third is equal to negative four X. 8 So now we can see that we have something that looks like a polynomial. 9 And when we have something like a polynomial, we can usually solve by factoring. 10 So maybe we can help ourselves out by adding the four X so that 11 everything is on one side and it's set equal to zero. 12 And then we noticed the first thing we can factor out right off the 13 bat is an X. And that becomes X to the fourth, 14 minus five X squared plus four. 15 Right? So one of our solutions would be X is equal to zero because 16 we have this X out to the side. However, 17 that is not an answer because we're told in the question that X has 18 to be greater than zero. So what we really need to do is take 19 this part that I've highlighted in yellow and factor it. 20 And this is easier than you may think. Um, 21 usually when we have something to factor, it starts out with an X squared. 22 So you would be normally used to something that looks like this. 23 And because it's an X squared, that's why we always start a Bible or 24 bubbles with just X, right? Because X times X gives us that X squared. 25 But in this cas...