Please help asap i will mark branlist

Which representation shows y as a function of x

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.  

To decrease an amount by 16% what single multiplier would you use

Which expression is equal to (f+g)(x)?