All Answers

+118725

Guest:
5^6*8^6

why can't you do this? You do need a calculator but there is one on this site.

it is just

(5 to the power of 6) x ( 8 to the power of 6) =

MelodyJan 23, 2014

+118725

tanker_girl777:
How do you know when a set of coordinates are a function... for example

{ (6,3), (5,2), (2,-3), (12,-12) }

also how would you map the relations of these coordinates?

(algebra 2 >.> I get messed up on the easy stuff)

In this set of points, every x value has a distinct y value, therefore it is a function.

If this point (8,3) was added it would still be a function

If (5,-4) were added it wouldn't be a function because the domain value of x=5 has 2 answers it could be 2 or it could be -4. do you want 2 or do you want -4, Total confusion. not a function.

when you are told to map the relations of these coordinates, you are just being asked to plot the points. That's all!

If you have a graph or a set of points mapped onto an xy plane, you can use the vertical line test to see if it is a function. (A vertical line goes straight up and down - not sideways)
You draw a vertical line anywhere at all on the number plane. If it only ever goes through 0 or 1 point on the graph then it is a function. If it EVER cuts the graph in 2 or more places then it is not a function, it will be a relation.

I hope that helps

MelodyJan 23, 2014

+5478

Imaginary numbers?

kitty<3Jan 23, 2014

+118725

mathgenius:
math is hard

Yes, sometimes it is.
but
sometimes it can be a lot of fun too

MelodyJan 23, 2014

+118725

jade_cas:
how do i get rid of a negstive x while searching for a limit?

You haven't given enough information. I need to see an entire question.

MelodyJan 23, 2014

1/2(8a+2) = 1

Divide both sides by half (1/2) to remove 1/2. Open the brackets and then proceed :)

GuestJan 23, 2014

+118725

0147852369:
if a fossil contains 1/16 of the carbon-14 it began with. how old is the fossil

Now you need to give me more information than that.
Maybe you are told, or maybe you are expected to look up what the half life is. Either way i am going to leave it until you give me more information.

MelodyJan 23, 2014

+118725

bott101:
How to do I solve for X in a problem such as log[15] n = log[15] (3n-2)

There is no X in your problem, but i assume that you want to solve for n

Why don't you start by dividing both sides by log[15]. Now, that would be a good idea.

MelodyJan 23, 2014

+118725

jamie_33:
if log(x) +log(x+3)=1, the solution is? please show work

first you have to use the identity that says
log(a) + log(b) = log(ab)

so you get

log(x(x+3)) = 1

Now I am going to assume that it is base 10

10 ^log(x(x+3)) =10 ¹

[ The 10 ^log cancel each other out ]

x(x+3)=1
etc

This is a web page with all the log identities on it that I refer to constantly. Maybe you should bookmark it.

http://en.wikipedia.org/wiki/List_of_logarithmic_identities

MelodyJan 23, 2014

The way I was taught to solve an equation like 95-x=26 was to isolate the variable (x) by moving terms around on each side of the = sign. When an term is moved from one side of the equal to the other it changes sign

ie

95 - x = 26
95 = 26 + x
95 - 26 = x
69 = x or x = 69

Just another method - always more than one way to skin a cat

GuestJan 23, 2014

+118725

Guest:
1/2(8a+2)=1

First multiply both sides by 2 and then think about what you need to do next

MelodyJan 23, 2014

+118725

kimberlydawn:
you want to purchase a car in 8 years and the cost is 87,000 and the APR is 6.5%. if you make monthly deposits, how much should you deposit each month to end up with 87,000 in 8 years

Ok Let me try to get this question straight.

You want to buy a car in 8 years. At the moment is costs $87,000 but each year the price will go up by 6.5%.
You make monthly deposits at the beginning of each month. You don't get any interest on you deposits. (This is a little strange, I wouldn't put my money in that bank account)
how much should you deposit every month to end up with $87,000 in 8 years.?

First you need to work out how much the car is going to cost in 8 yrs. This is a compound interest question so you have to use the compound interest formula. S=P(1+r) ⁿ
2'nd you need to know how many months are in 8 years.
Lastly you will need to divide the amount of money that you will need by how many months you have to save it in.

Now, see if you can do it yourself
If you can't you can post again but you will need to tell me what your problem is.

MelodyJan 23, 2014

#16

+56

Ya I'm sure there is, but this is just the way that I thought about it. I tend to overcomplify things and its not always good, but hey. It works!

WaltJan 23, 2014

+56

You sure this is a difference of cubes? 192 definitely isn't a perfect cube. The cube root of 192 is about 5.77 But anyways
8x ³ -192

(2x-5.77)(4x ²+11.54x+33.29)

WaltJan 23, 2014

#15

+118725

Thank you Walt,
there is a simpler way of putting your answer. Have a think about it.

And as for your question, you are welcome. I am lucky to have good maths friends that will help me out.

MelodyJan 23, 2014

2 triangles

Sides 4, 5, 6.40 and 3, 4, 5

GuestJan 23, 2014

#14

+56

Ok so I'm not an expert with explanations but I'll try to explain myself.

Ok so if we count up 10 random multiples of 4 like 24,48,12,16,20,96,28,32,36,40. Note that every time 4, 8, or 0 is the last number, the preceding integer is even. When 2 or 6 is the last number the preceding integer is odd. So now say we have a number like 712. Because 2 is the last number, whatever comes before it has to be an odd number which in this case is 1 and it is odd, So 712 is evenly divisible by 4. Now if this number were 722, because 2 is even, it would have to be followed be either a 0, 4,or 8, to be divisible. So 728, 724, and 720 are all divisible by 4. With this in mind someone can give you any set of numbers. Such as 9848795 (random number) because this number ends with an odd number, all you would have to change the 5 to a 2 or 6 and you have a multiple of 4.

Ok so as you can see with the multiples of four, none end in 1,3,5,7, or 9 so any big number ending with one of those is not perfectly divisible by 4. Now if it ends in 0,2,4,6 or 8 then just perform the little test and you can see if its divisible by 4. Ok so, to sum it all up,

All multiples of 4 end in 0,2,4,6, or 8. If it ends in 2 or 6, check to see if the number preceding is odd or even. If it is odd then that number is divisible by 4. If the number ends in 0,4, or 8 then check to see if the preceding number is even. If it is even then the number is divisible by 4.
So with that information is 476,850,436 divisible by 4?

P.S. Thanks for the help with my atrocity of a problem Melody.

WaltJan 23, 2014

#13

+118725

Guest:
Well, if I have a big number like 234, it is the same as 2x100 + 3x10 + 4 = 2x99 + 3x9 + 2 + 3 + 4.
The part 2x99 + 3x9 can obviously be divided by 9.
So if we can also divide 2 + 3 + 4 (the sum of the digits) by 9, the whole number can be divided by 9.