Răspuns :
6.
18=2×3²
75=3×5²
cmmdc=3
Ana are 3 prieteni
7.
2ⁿ⁺¹×3ⁿ+2ⁿ×3ⁿ⁺²+6×2ⁿ×3ⁿ=
=2ⁿ×3ⁿ×(2+3²+6)=
=2ⁿ×3ⁿ×(8+9)=
=2ⁿ×3ⁿ×17 deci divizibil cu 17
12.
7ˣ+7²ˣ+7ˣ⁺³=19257
7ˣ(1+7ˣ+7³)=7²×393
7ˣ(344+7ˣ)=7²×(344+49)
7ˣ(344+7ˣ)=7²×(344+7²)
x=2
18=2×3²
75=3×5²
cmmdc=3
Ana are 3 prieteni
7.
2ⁿ⁺¹×3ⁿ+2ⁿ×3ⁿ⁺²+6×2ⁿ×3ⁿ=
=2ⁿ×3ⁿ×(2+3²+6)=
=2ⁿ×3ⁿ×(8+9)=
=2ⁿ×3ⁿ×17 deci divizibil cu 17
12.
7ˣ+7²ˣ+7ˣ⁺³=19257
7ˣ(1+7ˣ+7³)=7²×393
7ˣ(344+7ˣ)=7²×(344+49)
7ˣ(344+7ˣ)=7²×(344+7²)
x=2