PSAT's

[Burter]

You should have gotten a booklet of everything that will on it when you signed up.

[Burter]

That was stupid. A test of this magnitude would require you to every resource you can get. I remember worshipping that booklet.

EDIT:

...and getting a very high score ^_^

[Ruhiel]

AGH! Bojack just mentioned that four-letter word.

I think you need to know a fair bit of trig, Bojack. I've taken 'bout 4 practice PSATs so far, and the big emphasis seems to be mostly on 30-60-90 triangles, 45-45-90 triangles, properties of isoceles and equilateral triangles, and triangles in comparison to other polygons. Mostly solving for unknown side lengths and areas of shaded regions.

Man, I am just going berserk here. My latest score on one of the practice tests was a 199, and I need to get up to a 215. I hate math with a passion *makes lots of stupid mistakes*

[Android-18]

Haha, losers.

<- Canadian.

[Ruhiel]

Can someone please explain some of these messed up exponential properties to me? I got a question wrong and still stand behind it, because the "correct" answer still seems like a load of bullshit to me.

Here was the question:

Simplify this Expression:

5^X * 2^(X+Y)

I said the answer was 10^(2X+Y) due to the additive property of exponents, but they claim the answer was 10^X * 2^Y.

[Banned Dana]

hehehe...high schoolers....

[Hellfighter 17]

Originally posted by Android 20
Can someone please explain some of these messed up exponential properties to me? I got a question wrong and still stand behind it, because the "correct" answer still seems like a load of bullshit to me.

Here was the question:

Simplify this Expression:

5^X * 2^(X+Y)

I said the answer was 10^(2X+Y) due to the additive property of exponents, but they claim the answer was 10^X * 2^Y.

If you aren't sure about an answer with variables, give the variable(s) /a value(s) and work it out. I'm assuming "^" is "to the power of."

5^X * 2^(X+Y)
= 5^2 * 2^(2+3)
= 25 * 2^(5)
= 25 * 32
= 800

You simplified expression:

10^(2X+Y)
= 10^[2(2)+3]
= 10^(4+3])
= 10^7
= 10 000 000

Their simplified expression:

10^X * 2^Y
= 10^2 * 2^3
= 100 * 8
= 800

With the original expression [5^X * 2^(X+Y)] you have to recognize that 5 is being multiplied by 2. And it's saying that 2 to a certain power is being multipled by 5 to a certain power. The powers are the same, so you can think of it just like 5^1 * 2^1, which would be 10^1, so that would be 10^X. But, you still had 2 to the power of Y, and since X and Y were added, you can simply just take the X out and leave a 2 ther,e leaving you with 10^X * 2^Y.

But, I am not a certified professor, so. . .

[Raz]

Wait... is that ^ supposed to be "or"? As in being involved in solving inequalities? I've heard a couple times that they would use something in place of "and" or "or" for these sort of things.

[Hellfighter 17]

Originally posted by Goten
Wait... is that ^ supposed to be "or"? As in being involved in solving inequalities? I've heard a couple times that they would use something in place of "and" or "or" for these sort of things.

Aren't inequality signs "=/=," ">," and "<." I'm pretty sure the "^" meant "to the power of."


Heh. *is the Canadian* ^_^

[Hellfighter 17]

If you have the question and the answer, math is relatively easy to figure out. That's why the math universe is the simplest of 'em all; a great place to escape that of our own.

Oh, and Bojack; I sure hope that trigonometry is on there. I have to take a class for a whole semester next year just on that. =/

[Ruhiel]

Yeah, but what I don't get yet HF is where that second X went?

Cuz there was an X over the 5 and an X over the two. You can't just make one disappear can you? (this is a problem I've always had. I can't accept a variable just "disappearing" >.<)

[Zarbon]

Originally posted by Android-18
Haha, losers.

<- Canadian.

Go Canada!

[Hellfighter 17]

Originally posted by Android 20
Yeah, but what I don't get yet HF is where that second X went?

Cuz there was an X over the 5 and an X over the two. You can't just make one disappear can you? (this is a problem I've always had. I can't accept a variable just "disappearing" >.<)

Okay. So imagine it was simply 5^X * 2^X. We'll see that X = 1, that means it is 5^1 * 2^1, which equals 10^1. So, that would be the same as 10^X, since X = 1.

[Ruhiel]

Alright then. I'll just remember to subsitute a constant in for x in each of those and then compare it to what it would be as a variable once simplified. That way my mind can't try and convince myself that I have to add exponents that are being multiplied by their bases.

Thankee Professor HF

[Hellfighter 17]

Originally posted by Android 20
Alright then. I'll just remember to subsitute a constant in for x in each of those and then compare it to what it would be as a variable once simplified. That way my mind can't try and convince myself that I have to add exponents that are being multiplied by their bases.

Thankee Professor HF

Yea, values can be quite useful at times. No problem, I learned to do that myself while I was explaining it, so I'm sure you can get this schtuff.

[Krillin]

Math sucks. I hate it with a passion.

I'm damn good at it too, try to figure that one out. I got a 2190 on my SATs (750 Verbal, 740 Math, 700 Writing). I got 99 percentile for PSAT's, though I didn't make it into the Semi-Finalist grading section of the Honor Society.

With that went a couple thousand dollars in scholarship money. >.>

[Minoshia]

5^X * 2^(X+Y)

10^2x+y

[Hellfighter 17]

Originally posted by Minoshia
5^X * 2^(X+Y)

10^2x+y

WTF?

[Minoshia]

oh fuck. **is realizing the ^ is not what i thought**

[Minoshia]

wait in multiplication, don't you add the exponents together. SO after you multipled the 5 and the 2, obviously. The two x's would combine to 2x. Addition and subtraction of exponents yields them not changing, but the standard number, aka 5 or 2, is changed. In multiplication i was pretty sure you added the commom exponents. Making it 10^2x then just the y. making it 10^(2x+y)? I was pretty sure in multiplication you add the exponents