What’s the actual sum of 5/6+1 4/12+7/12

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

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

Ahiker stands at an unknown elevation before he ascends 2 miles up a mountain to an elevation of 9 miles. find the elevation of the hiker before his ascent.