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vinay kumar

· started a discussion

· 1 Months ago

what formula is used for this problem

Question:
The value of the expression x4 –17x3 + 17x2 – 17x + 17 at x = 16 is – 
Options:
A) 0
B) 1
C) 32
D) 3
Solution:
Ans: (b)


Knowledge Expert

· commented

· 1 Months ago

Its totally on shortcut.....otherwise you can't simplify it in just 30 seconds by putting x=16 in the expression..Only Surds and Indices formula have been used....Nothing else....

x^4 –17x^3 + 17x^2 – 17x + 17

= x^4 –16x^3-x^3 + 16x^2 + x^2 – 16x -x + 17

Now, put, x=16

=16^4 –16*16^3-16^3 + 16*16^2 + 16^2 – 16*16 -16 + 17

=16^4 –16^4-16^3 + 16^3 + 16^2 – 16^2 -16 + 17

=-16+17 =1

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