Barron's Math II SAT Test Accuracy? + a few other questions

<p>Hey, I was just wondering how accurate the Barron's review book is for the Math II test. I took the diagnostic test and it says that i got an 800 (44 raw, but i had 3 or 4 lucky guesses). Somewhere I read that Barron's is much harder than the actual test but I got a very high score on this and I have the latest edition (9th) which might have been scaled down a bit to match the actual SAT. If anyone has seen both of these or knows anything about how accurate the tests are that'd be awesome.</p>

<p>I also have a few general questions about subject tests in general. I haven't looked over the review section of Barron's but in the diagnostic test it had questions about matrices? I learned these briefly a few years ago but have no recollection of anything I learned. My school doesn't teach these so I was hoping that Barron's decided to add these to the SAT review book to make people learn it and not because it's on the actual SAT. If the math II does cover anything in depth about them? Like Kramer's Law - the only thing i remember from the past...I don't know what it is, i just know it exists.
I'm aiming for 750+ on the math II, but i got a 740 on the regular SAT. I really don't wanna retake the SAT so is showing you know how to do math on the subject test good enough for colleges?
I'm pretty sure this is true, but I'm guessing the APUSH material and USH Subject test material are the exact same, with AP possibly being a little harder. Yes?
And last one, how close is the Chem subject test to AP? </p>

<p>Sorry for all the questions and stressing, but I'm taking the SAT's may 7 which is right in between AP testing as I can't take them in June, so I'm a tad nervous about all the studying/preparation. I know that I can probably find a lot of this info on different threads, but if anyone could answer these questions specifically that would be help me out a lot. Thanks.</p>

<p>EDIT: Hahaha after posting I looked at the topics below mine and like half of them were asking about Barron's. And also "Kramer's Law" is actually Chemistry thing...** Cramer's Rule** is the matrices thing. My bad...</p>