I think it easy to you pls do

Hi, can anyone show me how to do this problem? 100 points for this. in advance

Solve this problem! extra ! 3025/5.5 = a/90.75

Sanjay solved the equation below. which property did he use to determine that 7x+42=42 is equivalent to 7(x+6)=42 7x+42=42 7x=0 x=0