HELPPP ME PLSSs

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

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

Which of the following equations is of the parabola whose vertex is at (4, 3), axis of symmetry parallel to the y-axis and focus at (4, -3)? a.) y+3=1/24 (x+4)^2 b.)y-3=-1/24 (x-4)^2 c.)x-4=-1/24 (y-3)^2