Someone pls help me with these worksheets :< (Please answer properly, if u don't know, pls just ignore)

Answer the following for 896.31 cm= km 100cm = 1m 1000m = 1km a) 0.0089631 b) 0.0089631 c) 8.9631 d) 89.631

Factor -8x3-2x2-12x-3 by grouping what is the resulting expression?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.