Explanation for Question 17 From the Math (No Calc) Section on the Official Sat Practice Test 3
So here we're asked what is the value of X? 2 So essentially they want us to solve for X here. 3 We can do that first by combining like terms, 4 right. We see, we have two X terms right here, 5 which are already have a common denominator, which is really nice. 6 Um, and so those simplified a three over nine X and right away, 7 I would go ahead and simplify that cause I can divide both sides by 8 three. Um, 9 and so that would give us one over three X is equal to something 10 right now we have to combine like terms over here. 11 It won't be as quick because we don't have a common denominator, 12 but we can see that the common denominator, 13 our greatest common factor is going to be our greatest common, 14 multiple rather is going to be 12. So I can change the denominator on 15 my other fraction by multiplying everything by three. 16 So that this one becomes three over 12. And this one I'll just keep 17 is five over 12, and I'm adding them right in three plus five is 18 eight. So I have eight over 12, 19 which I can also simplify, um, 20 by dividing both sides by four and getting each two over three. 21 So now I just need to multiply both sides by one third or rather 22 by three, right? Because I have really, 23 this is X divided by three when I do X times one third. 24 Um, and so in order to cancel out this one third, 25 I need to multiply by three. And when I do that and that cancels 26 out, I get the X is equal to two.