Explanation for Question 6 From the Math (No Calc) Section on the 2020 October Sat
So question number six gives us a funky little equation that has degrees Celsius, 2 right? Which we're probably familiar with the see here. 3 It has the degrees ranking, which we probably haven't seen before, 4 but all we need to know is that the ranking is the R variable 5 and that's all that matters. We don't need much background knowledge here, 6 if any. And then we go into the question and it access asks us, 7 which of the following expresses the temperature and a ranking in terms of C. 8 So just a little bit about the language here, when it says expresses ranking, 9 that means we want the equation to be solved for R which you can 10 see here because all of the answer choices are solved for R R is 11 equal to something. And then what it says in terms of the temperature Celsius, 12 that phrase in terms of it's telling you what variables you're allowed to have 13 in the equation. 14 So when it says, in terms of Celsius, 15 that means that Celsius, the C is the only variable you're allowed to have 16 in your equation outside of what you're solving for, 17 which is our. So all we need to do is take this equation that 18 they've given us up here and sell for our instead of C. 19 And this can be done first by multiplying out the five nines. 20 You always want to get rid of what's in the parentheses. 21 First, we could do this by multiplying by nine over five on the sides. 22 Because if we do that, we see that these fives will cancel. 23 These nines will cancel and we'll be left with nine over five C is 24 equal to R minus 4 91 0.67. 25 Now, all we have to do is add 4 91 0.67 to both sides so 26 that we can get our on its own. And that 27 gives us nine over five C plus 4 91 0.67 is 28 equal to R and these two cancel. 29 And so the answer choice that shows us, that is going to be okay. 30 Great. Yep. So our correct answer is going to be a.