Simplifying the expression

spacewater

Junior Member
Joined
Jul 10, 2009
Messages
67
problem
\(\displaystyle \frac{(x^2+5)(\frac{1}{2})(4x+3)^\frac{-1}{2}(4)-(4x+3)^\frac{1}{2}(2x) } {(x^2+5)^2}\)

steps I've taken
\(\displaystyle \frac{\frac{(x^2+5)(\frac{1}{2})(4)-(4x+3)(2x)}{(4x+3)^\frac{1}{2}}}{(x^2+5)^2}\)

After multiplication on the numerator...
\(\displaystyle \frac{4x^3-8x^2+4}{(4x+3)^\frac{1}{2} }\cdot \frac {1}{(x^2+5)^2}\)

Final Answer
\(\displaystyle \frac{4(x^3-2x^2+1)}{\sqrt{4x+3}(x^2+5)^2}\)

The numerator threw me off. I just don't know how to approach this kind of problem. Can someone who isn't too busy teach me the steps to solve the numerator part? thanx
 
When you moved the (4x + 3)^(-1/2) down as (4x + 3)^(1/2), you have it under the FULL numerator:
should be under 2(x^2 + 5) only ; apart from that, you seem to be doing OK.

Example: 3*2^(-3) + 7 = 3/2^3 + 7 : got that?
 
Denis said:
When you moved the (4x + 3)^(-1/2) down as (4x + 3)^(1/2), you have it under the FULL numerator:
should be under 2(x^2 + 5) only ; apart from that, you seem to be doing OK.

Example: 3*2^(-3) + 7 = 3/2^3 + 7 : got that?

yeah that makes sense now thanks
 
Denis said:
When you moved the (4x + 3)^(-1/2) down as (4x + 3)^(1/2),

It is okay here because other part is multiplied by (4x + 3)^(1/2) to get (4x+3)^(1)

you have it under the FULL numerator:
should be under 2(x^2 + 5) only ; apart from that, you seem to be doing OK.

Example: 3*2^(-3) + 7 = 3/2^3 + 7 : got that?

correct - however following is also correct:

3*2^(-3) + 7 = (3 + 7*
2^3)/2^3
 
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