Răspuns :
Răspuns:
c=(2⁴⁰+2³⁹+2³⁸):7
c=2³⁸(2²+2+1):7
c=2³⁸·7:7
c=(2¹⁹)² → p.p
Răspuns:
[tex] ({2}^{40} + {2}^{39} + {2}^{38} ) \div 7 = {2}^{38} ( {2}^{2} + 2 + 1) \div 7 = {2}^{38} \times 7 \div 7 = {2}^{38} = ( {2}^{19})^{2} \: patrat \: perfect[/tex]