Explanation for Question 20 From the Math (Calc) Section on the Official Sat Practice Test 6
Question 20 asks us what is the, some of the solutions to X minus 2 six times X plus 0.7 is equal to zero. 3 Okay. So the solutions for this, 4 we're trying to figure out what values of X fulfill this equation. 5 So what can you plug in for X to get that this is equal 6 to zero one. 7 Hint here is that if you're multiplying two integers or even just two expressions, 8 if either one of these is equivalent to zero, 9 then the whole thing will be equal to zero because zero times anything is 10 just equal to zero. So what is the value of X to 11 get X minus six equals to zero. 12 So we can just set X minus six, equal to zero, 13 and we get that X is equal to positive six, 14 same thing for this other side, we have X plus 0.7 is equal to 15 zero. So then X is equal to negative 0.7. 16 So these are two different solutions to this equation. 17 And it's asking us for the sum of the solutions, 18 which means that we have to add them. So six plus negative, 19 0.7 and six minus 0.7. 20 That gets us to 5.3 and we can choose C as our answer.