Plz i wasn't at school when teached this

the steps for solving an equation are shown above. identify which property was used for each step.

What number should be added to the expression x^2+3x+ in order to create a perfect square trinomial? 3/2 3 9/4 9

Find the perimeter of the triangle with vertices  d(3, 4),  e(8, 7), and  f(5, 9). do not round before calculating the perimeter. after calculating the perimeter, round your answer to the nearest tenth.  

An internet company charges $8.95 per month for the first 3 months that it hosts your web site. then the company charges $11.95 per month for web hosting. how much money, in dollars, will the company charge for 8 months of web hosting?