Question

2.) 2abc{abc[abc(abc)^2]^2}^2

Answer 1

2a^15b^15c^15

Answer 2

In case you can't see where the answer comes from,
working from the inside to the outside, start with abc,
square and multiply by abc 3 times so the exponent goes to 3, to 7, to 15 (double and add 1), finally multiply by 2 to get the answer given by josephniel14 which I would write as 2(abc)^15.

Answer 3

2(a^15)(b^15)(c^15)