one way is to just expand it by using binomial theorem
or to use pascal's triangle
ok so
to find the nth term of a binomial, (a-b). where the binomial is to the r power you do
n-1=k
rCk times \((a)^{r-k}(-b)^k\)
and rCk=\(\frac{r!}{k!(r-k)!}\)
so
4th term
4-1=3
6 is exponent
6C3\((3x)^{6-3}(-2y)^3\)=
\(( \frac{6!}{3!(6-3)!} )((3x)^3(-8y^3)\)=
\(( \frac{6*5*4}{1*2*3} )(27x^3)(-8y^3)\)=
\((20)(27)(-8)(x^3)(y^3)=-4320x^3y^3\)
the 4th term is \(-4320x^3y^3\)
