[ProtoBaller1991]

g.e.d.'s are stoopid

[AlienBoy]

They are annoying i need to know a little bit about everything in math.

[pacasowithagun]

Originally Posted by AlienBoy

Trying to get my g.e.d but been stuck on math for 3 years.
Failed my math test 3 times.

Dividing whole numbers by decimals and mixed decimals.

How come when doing problems like 2,193 divided by .303

you dont put the decimal uptop 3 places to the right? the answer came out to 70237.7
I thought since you move the decimal over 3 spots you do that to the top answer... How come the decimal in 70237.7 is 5 spots over?
I thought it would be 702.377 because i moved the decimal 3 spots.
I'm confused on the place holder and how to bring it up in the right location...

1. The answer is not 70,237.7 I think you carried a 1 or something some where but it's supposed to be 7,237.7.

2. Why would you not use a calculator to do this?

[fock0]

About to knockout this short chapter and get some Magic hat. bababaababbaby

[AlienBoy]

Originally Posted by pacasowithagun

1. The answer is not 70,237.7 I think you carried a 1 or something some where but it's supposed to be 7,237.7.

2. Why would you not use a calculator to do this?

Half the test is calculator the other half is not calculator.

[dub CRISP]

easy, .303 is roughly 1/3 of 1
2193/.303 = 2193*3/1
2193*3 = roughly 6600
since .303 is less than a third of 1 you know your answer has to be around 7000

use mnemonics like that to check your answers to see if they seem right

[AlienBoy]

Having more trouble with a homework packet.

Equations involving ratio.

The length and width of a rectangle are in the ratio of 3 to 1. The perimeter is 80 feet. Find the length and width.

I keep getting the wrong answer but the answer sheet says Length 30 and Width 10.

[dub CRISP]

how do you get your answer?

[AlienBoy]

They provide a answer sheet on the back of the packet so i can check my answers. But if i can't solve the problem then theres no reason i should take the test if i can't solve on my own.

Anyways i'm taking a practice test on the internet and i'm stuck on this problem any help would be great.



One of the first electronic computers was in the shape of a huge box. It was 96 feet long and 2.5 feet wide. The amount of space inside was approximately 3,000 cubic feet. How many feet high was the computer?


I google'd how to find height.

It says Height * Width * Depth = Volume.
So i do 96 * 2.5 * 3000 = 720000

Then next step says
height = volume / (depth * width)

So i do 720000 divide by 98.5 ( i add 96 + 2.5 = 98.5)
And my answer is not one of the multiple choice answers.
Here is my selection of answers. I can't get any of these on my calculator.


A) 1.25
B) 12.50
C) 27.60
D) 125.00
E) 276.00

Help?

[Xanatos903 (Banned)]

The volume is 3,000 ft^3. Therefore, your equation should be this:

3000 = 96 * 2.5 * height (v = L * W * H)

Divide 3000 by 96 and 2.5, and you get 12.5 ft = height

Check your answer:

96 * 2.5 * 12.5 = 3000 ft^3

edit to add: You simply misplaced the unknown and the volume. Just get comfortable with a bit of rearranging to solve for "x" from there, and you should be set for any problems like that in the future.

For example, let me give you a couple that are a tad bit more difficult than that one. Just remember that 1 foot = 12 inches.

A box has a total volume of 5,000 cubic inches. Its length is 2.4 feet, its width is 2 feet. What is the box's height in feet?

To convert feet to inches, multiply it by 12. 



2.4 * 12 = 28.8in. 

2ft * 12 = 24 in 



Then from there, set up your equation. 



5000in = 28.8in * 24in * x (height) 

5000 / 28.8in = 24in * x 

173.61 = 24in * x

173.61 / 24in = x

7.23in = x 



Convert to feet: 



7.23in / 12 = .6 ft



Check answer: 



5000in = 7.23in * 28.8in * 24in (roughly, I didn't fiddle with too many decimals for simplicity) 

Problem 2:

A football field is covered in children so deep that it holds 64200 cubic yards of children. If a football field is 100 yards long, and 53.5 yards wide, how deep is the stack of children? Give answer in inches.

 

64200 yards = 100 yards * 53.5 yards * x yards (height)

12 yards = x 



Convert yards to feet, then inches. 



12 yards * 3 = 36 feet 

36 feet * 12 = 432 inches. 



Answer: The football field is covered 432 inches deep in children. This is approximately the same height as 6 grown-*** men standing on top of one another. 

[AlienBoy]

Was not expecting that fast of a response. Let me try and solve your problem.
one minute brain storming now.

So

5,000 divided by 2.4 then divide that by 2 = 1041.66667
Now somehow i got to convert that into feet.

So 1041.66667 * 12 ( beacuse 12 inches = a foot )
I get a crazy *** number which is 1250.00004

This doesn't look right.. hmm i must be doing a step wrong.

[Xanatos903 (Banned)]

Remember, the volume is in cubic inches. First you have to convert the length and width from feet to inches by multiplying them by 12.

[AlienBoy]

ahh okay let me try this. one minute


2.4 * 12 = 28.8
2* 12 = 24

5,000 / 28.8 / 24 = 7.2338

That the right answer?

Now i wil try and solve problem 2.
64200 yards so ugh...

64200 * 12 = 770400
100 * 12 =1200
53.5 * 12 =642

Now time for dividing

so 770400 in / 1200 in / 642 in = 1 inch?
Answer is the children are 1 inch deep?

[Xanatos903 (Banned)]

Yup, 7.23in is correct, but don't forget to give the answer in the units they ask for. I missed a lot of questions back in high school by not doing everything the instructions said to.

[AlienBoy]

What do you mean units they ask for?

Make sure to add inches at the end of the answer?

edit: can you teach me how to simplify? i forgot how.

[Xanatos903 (Banned)]

I asked for the answer in feet, so 7.23in would convert rougly to .6 feet.

And as far as simplification goes, it's a little hard to explain over a keyboard, but maybe a few examples will get you on your feet.

12/24 = 1/2
9/12 = 3/4
8/56 = 1/7
9/36 = 1/4

In a few words, you're just converting the first fraction into the second fraction. 9 can go into 36 four times, so since you have one 9, you can simplify it to 1/4.

Here are a few problems to try:

2/4 =
2/8 =
2/16 =
2/24 =
2/802 =
3/90 =
4/16 =
10/100 =
800/1600 =
60/180 =

1/2

1/4

1/8

1/12

1/401

1/30

1/4

1/10

1/2

1/3

[AlienBoy]

I mean algebra simplify

like 6x ( 3x - x ) that type of stuff.

[They Call Me Rain]

Originally Posted by AlienBoy

I mean algebra simplify

like 6x ( 3x - x ) that type of stuff.

12x^2

Order of operations.

Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Start by doing the parenthesis, 3x-x. That gives you 2x.

Then multiple by 6x.

6x(2x)=12x^2

[Xanatos903 (Banned)]

Okay, so to simplify the one that you just gave me, you're first going to distribute the 6x to both terms in the parentheses. So you end up with two answers which you'll stick back together to form the final answer.

6x * 3x = 18x^2
6x * -x = -6x^2

Stick them back together:

18x^2 - 6x^2

Now, you'll notice that they can be combined to give a final answer. If you had something like 18x^2 - 6x, you wouldn't be able to combine them because one is an x^2, and the other is a simple x.

So, just do simple subtraction, and you get 12x^2. So, 6x (3x -x) can be simplified to 12x^2.

Just something to note, whenever you've got two terms that can be combined in the parentheses (x and x, or x^2 and x^2, so on...), combine them before distributing the term outside the parentheses.

So, in this case, you'd actually have 6x(2x), and that simplifies to 12x^2.

As a more complex example, let's simplify 2x(3x^2 - 12).

2x * 3x^2 = 6x^3
2x * -12 = -24x.

6x^3 -24x | This is your final answer. Can't simplify an x^3 and an x beyond this point, so leave it at this.

A little more complex:

2x(3x^2 - 2) + 5x(2x^2 + 7)

Now you're going to distribute the two to the parentheses right next to it, and do the same with the 5. Then stick it all together, and combine like terms to get your final answer.

6x^3 -4x + 10x^3 + 35x

Combine like terms (the -4x and the 35x, and the 6x^3 and the 10x^3)

16x^3 + 31x

You can even do the same thing with x's and y's in the same equation, and I can give you a few examples and problems if you want. But for now, here are some problems to work:

1. 3x(10x - 12x^2) - 2x(2x + 4)
2. 2x(2x^400 + 12) + 2x(2x^399 +12)
3. 5x(10 + 12) - 6x(12x^2 - 10x)

Solutions:

1. -36x^3 + 26x^2 - 8x 

2. 4x^401 + 4x^400 +48x

3. -72x^3 + 60x^2 + 110x

Watch your signs. It may help to think of a negative like this:

3x(10x - 12x^2) + (-2x(2x +4))

Distribute the negative with the 2x, and you'll get the right sign every time.

[AlienBoy]

Alright thanks dude ill try and solve this when i wake up.

I fell asleep.

Problem
1.) 3x(10x - 12x^2) - 2x(2x + 4)

I do Parenthese first.
10x - 12x^2.
S0 12 * 12 = 24x.
10 - 24 = -14x
Next parentheses box.
2x+ 4 = 6x

Now i'm lost.
I have the 3x on the outside and then i have the -2x left.

so i think i do.
3x * -14 =-42
then 6x * -2x = -12
for a total answer of
-42 * -12 =504
I'm pretty sure i'm doing the steps wrong.

[Xanatos903 (Banned)]

The order of operations that he's talking about only applies when you've got two terms which can be combined in the same parentheses. 3x - x can be, since both are to the same power. But with the problems I gave you, it won't work that way. One thing that you can't do is take an x^2 down to an x. If it's an x^2, it stays that way for the entire problem (unless you're multiplying it by something with another x). Same with x, x^3, so on and so forth.

So just take the 3x and multiply it by everything in the parentheses directly beside it. You get 30x^2 and -36x^3. How I'm getting these numbers is that you multiply the coefficients (the numbers in front) first, and then add the number of X's together.

3x * 3x = 9x^2.

Repeat the same process for the -2x and what is in the parentheses right beside it, and you get -4x^2 - 8x

So, you've distributed the terms to their respective parentheses. Now you've got 4 terms that need to be stuck together so you can do a final simplification.

30x^2 -36x^3 -4x^2 - 8x.

Now, you can't just stick these all together because they've got x's in them. You have to combine the terms with the same exponents together to get your final answer. So let's look at the what we've got so far. There's only one term with an x, and only one term with an x^3, so we have to leave those as they are. But there are two terms with an x^2, so we can deal with those this way.

Keeping the same signs as they had previously, we get 30x^2 - 4x^2 = 26x^2. And that's as far as we can go, since we only have on term with an x^2, one with an x, and one with an x^3.

Bringing the other two terms that we couldn't do anything with down, we get our final answer, which is -36x^3 + 26x^2 - 8x.

Edit- It should be noted that unless we know what X is, simplifying beyond that is impossible. If we knew that x was 2, for instance, we could do it like this:

-36(2^3) + 26(2^2) - 8(2) = -200

But because we don't know what x is, we can't figure out what the final answer is. Just leave it as x^3, or whatever.