Răspuns:
Explicație pas cu pas:
b)
0,09¹⁴⁻ⁿ = 0.3² ( 0,3)² = 0,09
0.09¹⁴⁻ⁿ = 0,09 => 14 - n = 1 => n = 14 - 1 => n = 13
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c)
2⁵ x 0,5ⁿ x 8⁵ = 2¹⁵
2⁵ x ( 5/10)ⁿ x ( 2³)⁵ = 2¹⁵
2⁵ x ( 1/2)ⁿ x 2¹⁵ = 2¹⁵ l : 2¹⁵
2⁵ x 1 /2ⁿ = 1
2ⁿ = 2⁵ => n = 5
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d)
1,3ⁿ + 1,3ⁿ⁺¹ + 2 x 1,3ⁿ⁺² = 5.68 x 1,69⁴
1,3ⁿ x ( 1 + 1,3¹ + 2 x 1,3² ) = 5,68 x (1,3)²ˣ⁴
1,3ⁿ x 5,68 = 5,68 x 1,3⁸ l : 5,68
1,3ⁿ = 1,3⁸ => n = 8
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e)
0,2²⁴ + 0,2²³ + 0,2²² = 1,24 x 0,04ⁿ
0,2²² x ( 0,2² + 0,2 + 1 ) = 1,24 x 0,04ⁿ
(0,2²)¹¹ x (0,04 + 1,2) = 1,24 x 0,04ⁿ
0,04¹¹ x 1,24 = 1,24 x 0,04ⁿ l : 1,24
0,04ⁿ = 0,04¹¹ => n = 11
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f)
1,1³ⁿ⁺⁶ = 1,21ⁿ⁺⁹
1,1³ⁿ⁺⁶ = (1,1²)ⁿ⁺⁹
1,1³ⁿ⁺⁶ = 1,1²ⁿ⁺¹⁸ => 3n + 6 = 2n + 18
=> 3n - 2n = 18 - 6
=> n = 12
