Respuesta :
Answer: 672x³y⁶.
Step-by-step explanation:
Newton's binomial formula
[tex]\displaystyle\\\boxed {\sum\limits_{k=1}^n=C^{k-1}_na^{n-k+1}b^{k-1}}[/tex]
[tex]\displaystyle\\(2x+y)^9,\\Hence,\\a=2x\ \ \ \ b=y\ \ \ \ n=9\ \ \ \ k=7.\\C^{7-1}_9(2x)^{9-7+1}y^{7-1}=C_9^6(2x)^3y^6=\frac{9!}{(9-6)!*6!} *2^3x^3y^6=\\\\=\frac{6!*7*8*9}{3!*6!} *8x^3y^6=\frac{7*8*9}{1*2*3} *8x^3y^6=7*4*3*8*x^3y^6=\\\\=672x^3y^6.[/tex]
