Question

26 +21+16+.....+x=11 then x=?

Answer 1

Step-by-step explanation:

hope it helps you.....

Answer 2

Step-by-step explanation:

Sn=Sum of n term of an Ap

Sn=n/2(2a+(n-1)d)

11=n/2(2*26-5n+5)

11 =n/2(57-5n)

22=57n-5n^2

5n^2-57n+22=0

5n^2-(55+2)n+22=0

5n^2-55n-2n+22=0

5n(n-11)-2(n-11)=0

n=2/5(Not possible)

n=11

Tn=nth term of an Ap

Tn=a+(n-1)d

x=26+10*-5

=26-50

-24

Ans x= -24

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