1. ## The bionomial theorem

Heres a problem for ya. I can manage when the (ax) does not have a power, but not sure in this case.

Find the coefficient of $x^3$ in $( 3x^2 - 5/x ) ^3$

2. Originally Posted by mibamars
Heres a problem for ya. I can manage when the (ax) does not have a power, but not sure in this case.

Find the coefficient of $x^3$ in $( 3x^2 - 5/x ) ^3$
Interesting problem.

As a binomial expansion with a power of three, the coefficients of the terms will be 1, 3, 3, 1, and in this case, the second term is the one of interest:

$3(3x^2)^2\frac{5}{x}$

$135x^3$

3. Originally Posted by ecMathGeek
$135x^3$
- $135x^3$