without expanding, determine the ff
term free of y in (2x^2 y^4 + x^3 y^-2) ^15
tnx
hi kabayan!
find $\displaystyle n$ such that $\displaystyle y^{4(15-n)}y^{-2n}=y^0$
so basically, you only need to solve for $\displaystyle 4(15-n)+(-2n)=0$
once you've solve this, then find $\displaystyle \left(\begin{array}{r}15 \\ n \end{array}\right)(2x^2)^{15-n}(x^{3n})$