Algebra Help!

  • 0 votes

Show that x(squared)+4x+3/2  -  3x(squared)+1/6      = 6x+4/3            

I've worked this out with bits of help - please email if need more detail to answer but what are these type of questions called so i can find some online? Or even better can anyone please come up with some of their own so i can try and answer them????

Thanks X           

Posted Sun 3rd June, 2012 @ 12:46 by ellie

11 Answers

  • 3 votes

amy, im not sure how u got to that conclusion because i think that u ae slightly wrong. i got the answer by doing the following. .....

(x^2 + 4x + 3)                      (3x^2 + 1)

-------------------      _         --------------------        ==> multiply the right equation by 3

          2                                          6

3x^2  + 12x + 9                 (3x^2 + 1)

--------------------        _    --------------------      ==> same denominators therefore simplify

           6                                    6 

   12x + 8

---------------    ==>  can cancel out 2 from top and bottom

      6

(6x + 4)

----------  ==> n that is ur answer 

      3

P.S thanks to amy for the inspiration to answer the question in that style ;D

Answered Sun 3rd June, 2012 @ 18:27 by Braniac
  • 0 votes

I think they're just algebraic fractions. Go on mymaths or samlearning and they have quite a few questions to answer =)

Answered Sun 3rd June, 2012 @ 15:15 by Joanne
  • 0 votes

I can't get it to equal 6x+4/3

But here's my attempt...

x2+4x+3         3x2+1

----------   -   ----------

     2                  6

x2/2 + 2x + 3/2 - x2/2 + 1/6 = 2x + 4/3

Answered Sun 3rd June, 2012 @ 16:33 by Amy
  • 0 votes

I think this is how you do it:

x₂ + 4x + 3 (times all by 6 and 3 so by 18) - 3x₂ + 1 (times both by 2 and 3 so by 6)

___________                                              ________

        2                                                          6

so you get:

18x₂ + 72x + 54 - 18x₂ + 6       this is just the left hand side of the equation

the right hand side:

= 6x + 4 (times both by 2 and 6 so by 12)

   _______

       3

= 72x + 48

so the equation reads:

18x₂ + 72x + 54 - 18x₂ + 6 = 72x + 48

simplify it to:

72x + 60 = 72x + 48

60 = 48

= 12

Hope it isn't too confusing, but it's hard to do on the computer :/

Answered Sun 3rd June, 2012 @ 19:25 by Joanne
  • 0 votes

umm joanne, plzz dont take this to heart but i think ellie's question was Show that x(squared)+4x+3/2  -  3x(squared)+1/6      = 6x+4/3  

Not to solve it  but nice to think round the box =D        

Answered Sun 3rd June, 2012 @ 20:10 by Braniac
  • 0 votes

Oh sorry! Just shows that you need to read the question ;)

Answered Sun 3rd June, 2012 @ 22:06 by Joanne
  • 0 votes

Yeah, what you did was exactly how I just did it :)

Answered Sun 3rd June, 2012 @ 22:11 by Joanne
  • 0 votes

yh lol but u seem to went further then wot the question asked LOL XD ***

Answered Sun 3rd June, 2012 @ 22:23 by Braniac
  • 0 votes

thanks guys! can anyone be even more helpful and come up with a similar question that i can solve just to get the hang of it???X

Answered Mon 4th June, 2012 @ 09:24 by ellie
  • 0 votes

I have a 'solve' one for you:

Solve            4           3      

                _____  +  _____    = 1

                x + 3      2x - 1

Answered Mon 4th June, 2012 @ 19:23 by Joanne
  • 0 votes

That is quite a easy question. firstly u want to find the lowest common denominator which is (x+3)(2x-1)

So what u do is u multiply everything by that common denominator and this is what u should get:

   4                                              3   

-------    X  (x+3)(2x-1)     +   ------------     X  (x+3)(2x-1)   =  1 X (x+3)(2x-1)

x+3                                          2x-1  

Now u can see that there are some common factors that can be cacelled out  like the denominators can cancel outwith the LCD u are multiplying by (the part in bold). Then u are left with this:

[4 X  (2x-1) ]  + [3  X  (x+3)  ]  = (x+3)(2x-1)

Then expand the brackets and simplify! 

11x +  5 = 2x^2  + 5x -3

Then make onee side equal zero so u get the following:

2x^2  - 6x  - 8 = 0

Factorise the equation !!!!

(2x-8)(x+1)

therefore:

x=4 or  x=-1

Answered Tue 5th June, 2012 @ 20:46 by Braniac