Question

7 la x + 7 la 2x + 7 la x+3 = 19257 .

Answer 1

dam factor comun pe $7^{x}$

$7^{x}$ (1 +  $7^{2}$ + $7^{3)}$ = 19257
$7^{x}$ (1+49 + 343) = 19257
$7^{x}$ * 393 = 19257
$7^{x}$ = 19257 / 393
$7^{x}$ = 49
$7^{x}$ = $7^{2}$

Answer 2

noteaza 7 la x cu t si ecuatia va deveni:
t+t²+343t=19257
t²+344t-19257
Δ=118336+77028=195364, √Δ=442
t₁=49, tlax=7², x=2
t₂=-393 imposibil deoarece trebuie ca t>0,