सदस्य: Melody

Andrea:
A bus trip has three stages. The first stage takes 21/3hours, the second stage takes 2 1/2 and the third stage takes 3 3/4 hours.how many hours does the trip take ?

That is just an addition problem.

2 + 1/3 + 2 +1/2 + 3 + 3/4 =
add up all the whole number parts first.
2+2+3 = 7
so we have
7 + 1/3 + 1/2 + 3/4
To add up all the fractions you have to find the lowest common denominator. that is the smallest number that 3,2,and 4 all go into. And, the answer is 12.
change each of those fractions to 12ths and then add the tops together. but remember 12/12 = 1 So the answer to the fraction bit will be 1+some twelths
when you get this answer add it to the 7 and you will have your answer.

If you are very clever, you could even turn the fraction answer into minutes.

OR you could have turned the fractions into minutes in the original question and added the minutes (not worrying about the fractions any more)
How many minutes is 1/2 an hour?
How many minutes is 3/4 an hour?
How many minutes is 1/3 an hour?
Can you work it our

Melody19 Jan 2014

+118691

gdd:
(8x-2)(4x)

I won't do your one, I will do a different similar one.

(6-15x)(3x)

=3x(6-15x)

Now you have 3x lots of 6-15x
which means that you have
=3x lots of 6 take away 3x lots of 15x

= 3x times 6 - 3x times 15x

= 18x - 45xx

= 18x - 45x ²

now you can do your one

Melody19 Jan 2014

+118691

Zozo:
Determine the values of x for the following x^4 - 6x^2 +6 = x^2+ 6x +6 .?

i'd start by taking it all to one side.

x ⁴ - 7x ² - 6x = 0
Then i'd do any easy factorising

x(x ³ - 7x - 6) = 0
now I can see that one answer is x=0

to get the other answers, and there could be 3 of them (because of the x ³)
i would try to factorise 1x ³ - 7x - 6

Any integer root will be a factor of -6/1 = -6 that is, it could be 1, -1, 2, -2, 3, -3, 6, -6 there are no other choices. (The root could of course be a non integer)

f(x) = x ³ - 7x - 6
f(1) = 1-7-6 not equal to 0 doesn't help
f(-1) = -1+7-6 = 0 therefore (x+1) is a factor and x=-1 is a solution to the original equation.
at this point I could do an algebraic division before i look for the next root but i might just continue here and see if I can find another one easily

f(2)=8-14-6 not equal to zero
f(-2)= -8+14-6 = 0 therefore (x+2) is a factor and x=-2 is a solution to the original equation
Again i could do an anlgebraic division but I'm going to see if I can continue my lucky streak here.

f(3)=27-21-6=0 therefore (x-3) is a factor and x=3 is a solution to the original equation.
that's it, i knew that there could not be more than 3 more roots. so I have them all.

So the 4 roots are x=0, x=-1, x=-2, and x=3

If I graphed y = x ⁴ - 7x ² - 6x this is what I get.

Melody19 Jan 2014

+118691

Eveline Ogborne:
what is 2%x30x92800

2% = 2/100 = 0.02

so it will be 0.02 x 30 x 92800

Melody19 Jan 2014

+118691

vv331pie:
:?: how do you divide decimals? for a kid in 6th grade?

Hi vv331pie,

1). Are you good at normal division, if not then you need to practice this
2) To divide a decimal by a whole number you just do it the normal way but you have to be careful to keep the decimal point in the same place.

for example 148 divided by 2 = 74 You need to set these out in the normal way to see what I am saying, unfortunately it is very difficult for me to do this on this site.
anyway, 14.8 divided by 2 = 7.5 and 1.48 divided by 2 = 0.74 (If you don't understand what I mean, watch the video and then you might. )

3) do you know how to multiply decimals by powers of 10
for example 0.854 x 10 = 8.54 I moved the decimal point over 1 place because there is 1 zero in 10
13.0609 x 1000 = 13060.9 I moved the decimal point over 3 places because there are 3 zeros in 1000
12.7 x 100 = 1270 there is an invisable decimal point on the end but I don't need to show it because it has become a whol number.

4) Watch the video. (To do this you have to highlight the address and copy it into the address line at the top of your page and then press 'enter'. Do you know how to do this?

http://www.youtube.com/watch?v=mnCPjLDOAEI

Get back to me after you do this and we'll try some examples. You can also tell me if you think you understand, if you don't understand maybe we can start at an earlier spot. .
--------------------------------------
ps. There was no need to post your question twice. Maybe you wanted to add in the 6th class bit in the title, if you sign up properly (maybe you already have) you can change things like this without making an entirely new post.

Melody19 Jan 2014

+118691

sakhgdaskhf:
P(2)=3 P(x)= 2x+3=?

Your question doesn't make sense.
If P(x)=2x+3 then P(2)=2*2+3 = 7

Melody18 Jan 2014

#10

+118691

+23

Helpers today were DJ-7809, Habndbdk and sportsguy007.
Thanks folks.

Melody18 Jan 2014

+118691

Here are the approx roots from graphing

140118 difficult roots.JPG

Melody18 Jan 2014

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