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  1. If x2 – 3x + 1 = 0, then the value of
    x6 + x4 + x2 + 1
    will be
    x3

    1. 18
    2. 15
    3. 21
    4. 30
Correct Option: C

x2 – 3 x + 1 = 0
⇒ x2 + 1 = 3 x

x2 + 1
= 3
x

⇒ x +
1
= 3 ........... (i)
x

∴ Expression =
x6 + x4 + x2 + 1
x3

Expression =
x6
+
x4
+
x2
+
1
x3x3x3x3

Expression = x3 + x +
1
+
1
xx3

Expression = x3 +
1
+ x +
1
= 2 × 2 = 4
x3x

Expression = x +
1
3 - 3 . x .
1
x +
1
+ x +
1
xxxx

Expression = 33 – 3 × 3 + 3 = 27 – 9 + 3 = 21



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