Question

a=(20^40+2^39+2^38):7este patrat perfect

Answer 1

$a = ( {2}^{40} + {2}^{39} + {2}^{38} ) \div 7$

$a = [ {2}^{38} ( {2}^{2} + 2 + 1)] \div 7$

$a =[ {2}^{38}(4 + 2 + 1) ] \div 7$

$a = ( {2}^{38} \times 7) \div 7$

$a = {2}^{38} \times (7 \div 7)$

$a = {2}^{38} \times 1$

$a = {2}^{38}$

$a = {2}^{19 \times 2}$

$a = { ({2}^{19} )}^{2} = > p.p$