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+118725

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.

MelodyJan 19, 2014

+118725

Eveline Ogborne:
what is 2%x30x92800

2% = 2/100 = 0.02

so it will be 0.02 x 30 x 92800

MelodyJan 19, 2014

+118725

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. .
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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.

MelodyJan 19, 2014

Jan 18, 2014

It depends on the shape you are trying to find the volume for!
Ex.1 a rectangular prism- length x width x height (l x w x h)
Ex.2 a cone- (1/3) x (area of base) x height
Ex.3 Cylinder- (area of base) x height

GuestJan 18, 2014

AA22:
Look at the second part of the question (the fraction you are dividing by). Swap the numerator and the denominator numbers around (so if 6 used to be on the top and 10 used to be on the bottom, 10 will now be on the top and 6 will be on the bottom). Doing this turns the question from division to multiplication! Continue by multiplying the two fractions! Hope this helped

****sorry first turn the decimals into fractions. To do this you just put a 1 under the number

GuestJan 18, 2014

Look at the second part of the question (the fraction you are dividing by). Swap the numerator and the denominator numbers around (so if 6 used to be on the top and 10 used to be on the bottom, 10 will now be on the top and 6 will be on the bottom). Doing this turns the question from division to multiplication! Continue by multiplying the two fractions! Hope this helped

GuestJan 18, 2014