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  1. If x +
    1
    = 1 ,then ( x + 1 )5 +
    1
    equals
    x + 1( x + 1 )5

    1. 1
    2. 2
    3. 4
    4. 8
Correct Option: B

x +
1
= 1
x + 1

Adding 1 on both sides ,
⇒ ( x + 1 ) +
1
= 2
( x + 1 )

On squaring,
⇒ ( x + 1 )2 +
1
+ 2 = 4
( x + 1 )2

⇒ ( x + 1 )2 +
1
= 2 ...(i)
( x + 1 )2

Again, cubing , ( x + 1 ) +
1
= 2
( x + 1 )

⇒ ( x + 1 )3 +
1
+ 3( x + 1 ) +
1
= 8
( x + 1 )3( x + 1 )

⇒ ( x + 1 )3 +
1
= 8 – 3 × 2 = 2
( x + 1 )3

( x + 1 )2 +
1
( x + 1 )3 +
1
= 2 × 2 = 4
( x + 1 )2( x + 1 )3

⇒ ( x + 1 )5 + ( x + 1 ) +
1
+
1
= 4
( x + 1 )( x + 1 )5

⇒ ( x + 1 )5 +
1
= 4 – 2 = 2
( x + 1 )5

Second method :
Here, x +
1
= 1
x + 1

⇒ ( x + 1 ) +
1
= 2
( x + 1 )

∴ ( x + 1 )2 +
1
= 2
( x + 1 )2



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