What expression has the value of 39

Express in the simplest form: (x^2+9x+14/x^2-49) / (3x+6/x^2+x-56)

Which of these side lengths could form a triangle a) 2 cm , 2 cm , 4 cm b) 3 cm , 5 cm , 10 cm c) 3 cm , 4 cm , 5 cm d) 4 cm , 8 cm , 15 cm

Which equation represents h for right triangle abc