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