If x be the real number such that x3+4x = 8 then the value of the expression x7 + 64x2 is
1. 124
2. 125
3. 128
4. 132
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1 Answers
Lokesh Verma
·2010-07-27 05:08:58
Hint:
x3=8-4x
x7=8x4-4x5
Hence the given expression is -4x5+8x4+64x2
Now try to simplify further.....