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Question Number 140834 by greg_ed last updated on 13/May/21

hi, sirs !  please, how to solve this thing below (a ∈ R)            { ((x_1 −x_2  = a)),((x_2 −x_3  = 2a)),((.................)),((.................)),((................)),((x_(n−1) − x_n  = (n−1)a)),((x_1 + x_2 + ... + x_(n−1) + x_n  = na)) :}

hi,sirs!please,howtosolvethisthingbelow(aR){x1x2=ax2x3=2a..................................................xn1xn=(n1)ax1+x2+...+xn1+xn=na

Commented by Rasheed.Sindhi last updated on 13/May/21

Adding all the equations:  x_1 +x_n =a(1+2+...+n)  x_1 +x_n =((n(n+1)a)/2)  .....  ...

Addingalltheequations:x1+xn=a(1+2+...+n)x1+xn=n(n+1)a2........

Commented by prakash jain last updated on 13/May/21

  x_1 =x_1   x_2 =x_1 −a  x_3 =x_2 −2a=x_1 −(a+2a)  x_4 =x_1 −(a+2a+3a)  ...  x_n =x_1 −(((n−1)n)/2)a  Σ_(i=1) ^n x_i =nx_1 −Σ_(i=1) ^n i(i−1)a  =nx_1 −aΣ_(i=1) ^n i^2 −aΣ_(i=1) ^n i  =nx_1 −((n(n+1)(2n+1)a)/6)−((n(n+1))/2)a  =na (given)  x_1 =a+(((n+1))/2)a+(((n+1)(2n+1))/6)a  =(a/3)(n^2 +3n+5)  x_i =x_1 −((i(i−1))/2)×a

x1=x1x2=x1ax3=x22a=x1(a+2a)x4=x1(a+2a+3a)...xn=x1(n1)n2ai=1nxi=nx1ni=1i(i1)a=nx1ani=1i2ani=1i=nx1n(n+1)(2n+1)a6n(n+1)2a=na(given)x1=a+(n+1)2a+(n+1)(2n+1)6a=a3(n2+3n+5)xi=x1i(i1)2×a

Commented by Rasheed.Sindhi last updated on 13/May/21

W∈LCOM∈ SIR  after long interval!

WLCOMSIRafterlonginterval!

Commented by Ar Brandon last updated on 13/May/21

Greetings Sir Prakash Jain.  😃

GreetingsSirPrakashJain.😃

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