Several Mathematics problems?

If anybody would like to tell me the solutions and methods for these math problems I would be very grateful.1. If sinx= 5/13 , and pi/2 < x < pi , then sin 2x= ???2. This one might be confusing..------ (10/(x+1)) / (.5 + (3/(x+1)))3. simplify (x+2) +( (x^2-9x-22)/(x^2-121) )SOLVE4. 2cos^2(x)-5cosx-3=05. sin2x=cosx6. simplify--- ((x+y)/x) / (x^-1) + (y^-1)----- Thanks!