quick Q 2: can i simplify 4x^2+15x/6x^3 to 2+15x/3x to...

[holdyourhorsiieees]

what about 4x^2 + 15x/6x^3, can i simplify that to 2+15x/3x, then cancel out the 3x with the 15x, leaving 2+5 on top, making my final answer 7. is that "legal" too?

thanks so much. it's hard trying to remember stuff from 2 years ago and i keep on second guessing myself.

i appreciate the help! :]

 

[Mrspi]

Re: quick, simple question part 2

what about 4x^2 + 15x/6x^3, can i simplify that to 2+15x/3x, then cancel out the 3x with the 15x, leaving 2+5 on top, making my final answer 7. is that "legal" too?


thanks so much. it's hard trying to remember stuff from 2 years ago and i keep on second guessing myself.

i appreciate the help! :]

Uh, no.

consider this....

2 + 3
-------
2

Would you "cancel" out the 2's and end up with 3? Is 5/2 equal to 3? I don't think so.

You can divide both numerator and denominator by a common factor, but in the example I just gave, 2 is NOT a factor of both numerator and denominator.

For

4x<SUP>2</SUP> + 15x
----------
6x<SUP>3</SUP>

you need to start by factoring both numerator and denominator. THEN, see if there are any common factors that can be divided out.

x(4x + 15)
-----------
x*x*x*2*3

The only factor common to both numerator and denominator is x. You can divide this factor out, leaving you with

(4x + 15)
-----------
6x<SUP>2</SUP>

There are now no factors common to both numerator and denominator, so the fraction is simplified as much as it can be.

 

[holdyourhorsiieees]

omg. i don't know what i was thinking!!

duuuuuh!


thanks mrspi!