Explanation for Question 32 From the Math (Calc) Section on the Official Sat Practice Test 6
Okay. Question 32 gives us this expression and then it asks what 2 value of X satisfies the equation above. 3 Okay. So to solve this one, why don't we try and simplify down this 4 expression further and see if we can get to an answer we've 5 got two times five X minus 20 minus 15, 6 plus eight X is equal to seven. 7 So let's multiply out this two and we get two times five X is 8 equal to 10 X, and then two times negative 20 is going to be 9 negative 40. And then to get rid of these parentheses, 10 we have to remember to distribute this negative sign to both terms. 11 So we have negative 15 and then we have minus eight, 12 X is equal to seven. 13 So let's move like terms together. We have 10 X minus eight X minus 14 40 minus 15 is equal to seven. 15 So 10 X minus eight X is going to be two X and then 16 40 minus 15, or actually, 17 excuse me, it's going to be negative 40 minus 15. 18 It's going to be negative. 55 is equal to seven. 19 So let's add 55 to both sides. 20 And then we'll get to ax is equal to 62 and 21 then divide both sides by two, we get that X is equal to 31 22 and that's going to be the answer that satisfies the equation.