Which could be the first step in simplifying this expression? Check all that apply.

(x cubed x Superscript negative 6 Baseline) squared
(x Superscript negative 18 Baseline) squared
(x Superscript negative 3 Baseline) squared
(x Superscript negative 2 Baseline) squared
x Superscript 6 Baseline x Superscript negative 12 Baseline
x Superscript 5 Baseline x Superscript negative 4