Question

Choose the simplified form of  the fifth term of 6C4(2x)2(-y2)4.​

Answer 1

You didn't give us the choices.   It doesn't matter.  I think you're trying to write

$\displaystyle {6 \choose 4} (2x)^2 (-y^2)^4$

$= \dfrac{6!}{4! 2!} ( 4x^2 y^8)$

$= \dfrac{6(5)}{2} ( 4x^2 y^8)$

$=60x^2 y^8$

Answer: 60 x² y⁸