Question

BRAINLIEST pleae help!!!

Answer 1

I had a whole answer and my tab crashed.  Hate that.

We'll use the known sum of the first n natural numbers,

$\displaystyle \sum_{k=1}^{n} k = \dfrac{n(n+1)}{2}$

Let a be the first number, the one we seek.

$\displaystyle 3^9= \sum_{k=0}^{26} (a+2k) = 27a+ 2 \sum_{k=1}^{26}k$

$\displaystyle 3^9=27a+2(26)(26+1)/2$

$3^9=27(a+26)$

$3^6= a+ 26$

$a = 3^6 - 26$

$a = 703 \quad\checkmark$