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  1. If x +
    1
    = 3 , then the value of x5 +
    1
    is
    xx5

    1. 322
    2. 126
    3. 123
    4. 113
Correct Option: C

Using Rule 1 and 8,

x +
1
2 = x2 +
1
+ 2
xx2

⇒ x2 +
1
= 9 - 2 = 7
x2

Again ,
x +
1
3 = x3 +
1
+ 3x +
1
xx3x

⇒ 27 = x3 +
1
+ 3 × 3
x3

⇒ x3 +
1
= 18
x3

x2 +
1
x3 +
1
= 7 × 18 = 126
x2x3

⇒ x5 + x +
1
+
1
= 126
xx5

⇒ x5 +
1
= 126 – 3 = 123
x5



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