\(\sqrt{\left(x-2015\right)^{14}}\)+\(\sqrt{\left(x-2016\right)^{10}}\)=1

=>(x-2015)^7=<1

(x-2016)^10=<1

=>x=<2016

A=1-\(\frac{1}{2}\)+\(\frac{1}{2}\)-\(\frac{1}{3}\)+\(\frac{1}{3}\)-\(\frac{1}{4}\)+...+\(\frac{1}{49}\)-\(\frac{1}{50}\)

  = 1-\(\frac{1}{50}\)

  = \(\frac{49}{50}\)

c) Ta có : AH = DE ( vì ADHE là hcnhật ) 
AH^2 = BH.BC 
Suy ra AH^4 = HB^2 .HC^2 = BD.BA . CA.CE 
Vậy AH^3 = BD. CE . BC ( vì AH.BC = AB.AC ) 
 

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