Pls pls help me this was due two days ago.

Which function has the same domain as y=2x

Which is the standard form for this number? (4 x 1 100 ) + (8 x 1 1,000 ) + ( 3 x 1 100,000 ) ? a) 0.004803 b) 0.04803 c) 0.0483 d) 0.483

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.