X+12.5=18 = ??? Please Help

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.  

Atotal of 766 tickets were sold for the school play. they were either adult tickets or student tickets. there were 66 more student tickets sold than adult tickets. how many adult tickets were sold?

Asporting good store is offering 30 percent off of the original price(x) of football cleats. the discount will be reduced by an another $7 before sales tax.