IF A = 2^65, B=2^64+2^63+............+2^1+ 2^0and C=2^64+2^63+.....+2^2 +2^1 then prove that
2A =B+C+3...
Answers
||✪✪ QUESTION ✪✪||
IF A = 2^65, B=2^64+2^63+............+2^1+ 2^0and C=2^64+2^63+.....+2^2 +2^1 then prove that
2A =B+C+3... ?
|| ✰✰ ANSWER ✰✰ ||
Given,
→ A = 2^65 ---------- Equation ❶
→ B = 2^64+2^63+............+2^1+ 2^0
Here, we can see That, B is in GP, with
→ First term (a) = 2^0
→ r = 2
→ n = 65
Using GP sum formula :-
➼ Sₙ = a(rⁿ - 1)/ (r - 1)
putting values we get,
→ Sₙ = 2^0 ( 2^65 - 1) /(2-1)
→ Sₙ = (2^65 - 1) (since a^0 = 1 )
→ B = (2^65 - 1) ------------------ Equation ❷
Similarly,
→ C = 2^64+2^63+.....+2^2 +2^1
→ C = 2^1(2^64 - 1) /(2 - 1)
→ C = 2(2^64 - 1)
→ C = ( 2^65 - 2 ) ---------------- Equation ❸
________________________
Now, we have to Prove ,
➻ 2A = B + C + 3
Putting values From Equation ❶, ❷ and ❸ , we get,
➻ 2(2^65) = (2^65 - 1) + (2^65 - 2) + 3
➻2*2^65 = 2^65 + 2^65 - 3 + 3
➻2^66 = 1*2^65 + 1*2^65
Using [p(a)^n + q(a)^n = (p + q)a^n] in RHS now,
➻2^66 = (1+1)(2^65)
➻ 2^66 = 2 * 2^65