Question

4 Arătaţi că numărul a :vă rog urgent​

Answer 1

Răspuns:

a = (3²¹+3^20 +3^19):39

a = (9+3+1)•3^19:39

a = 13•3^19:39

a = 3^19/3

a = 3^18

a = (3^9)² → patrat perfect

==EVERGREEN==

Answer 2

Răspuns:

Explicație pas cu pas:

$\bf a= \big(3^{21}+3^{20}+3^{19} \big): 39$

$\bf a= 3^{19} \cdot \big(3^{21 - 19}+3^{20 - 19}+3^{19 -19 } \big): 39$

$\bf a= 3^{19} \cdot \big(3^{2}+3^{1}+3^{0} \big): 39$

$\bf a= 3^{19} \cdot \big(9+3+1 \big): 39$

$\bf a= 3^{19} \cdot 13: 39$

$\bf a= 3^{18} \cdot 3 \cdot \: 13: 39$

$\bf a= 3^{18} \cdot 39: 39$

$\bf a= 3^{18} \cdot 1$

$\bf a= 3^{18} = \red{\big( 3^{9} \big)^{2} \implies patrat \: perfect}$