What is the greatest common factor for 12& 15

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

Divide the following fractions 3/4 ÷ 2/3 1/2 8/9 9/8 2

Jose predicted that he would sell 48 umbrellas. he actually sold 72 umbrellas. what are the values of a and b in the table below? round to the nearest tenth if necessary