Varianta 1 de scriere a expresiei:
[tex]E=(-1)^{n} *11 -(-1)^{n}+1*(-4) + (-1)^{n}+3*9[/tex]
Cazul n = numar par:
[tex]E=1*11-1-4+1+27 = 11-1-4+1+27 = 34[/tex]
Cazul n = numar impar:
[tex]E=-1*11+1-4-1+3*9=-11+1-4-1+27=12[/tex]
Varianta 2 de scriere a expresiei:
[tex]E=(-1)^{n}*11-[(-1)^{n}+1]*(-4) + [ (-1)^{n}+3]*9[/tex]
Cazul n = numar par:
[tex]E=1*11-[1+1]*(-4)+[1+3]*9=11+8+36=55[/tex]
Cazul n = numar impar:
[tex]E=(-1)*11-[-1+1]*(-4)+[-1+3]*9=-11-0+18=7[/tex]
