Explanation for Question 24 From the Math (Calc) Section on the 2017 May Sat
Question 24 says for five things are going to even integers. 2 The, some of the first third integers is 20, 3 less than three times the fourth integer, 4 what is the fifth integer? That sounds great, 5 but let's take it step by step. So we have first, 6 the five consecutive even integers. 7 If we call the first one X, the next one would be X plus 8 two, then X plus four, 9 explosive six, and then X plus eight, 10 essentially our first and then the next, 11 even integer. And so on. Now, 12 what we're trying to find is the fifth integer or the X plus eight 13 to do that, we have to find X. So it says the sum of 14 the first and third integer is 20, 15 less than three times the fourth integer. 16 So if we have the, 17 some of the first and third that's X plus X plus four, 18 that is 20 less. 19 So plus 20, 20 then three times or fourth integer, 21 which is X plus six. So this which is the first part, 22 plus 20 has to be equal to the second part. 23 Um, because this is 20, less than that. 24 So we have to add 20 to make them equal. Now we just solve 25 for X. We have two X plus 24 equals 26 three X plus 18. 27 And now we combine like terms by putting the Xs on one side of 28 the numbers on the other. So the integers on the other subtract 18 from 29 both sides, we get six. So doing negative 18, 30 negative 18, and then subtract two X from both sides. 31 You got X. So we know that X equals six. 32 Now, if we know X equals six, and we're looking for the fifth and 33 to drug, which is X plus eight, we just have six plus eight 34 or four teeth B.