Question

QUESTION - 7. Value of k if (-2)^(k+1) × (-2)^3 = (-2)^7 is 4. (Hint:- a'2 --> means "a" to the power 2] F OT
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Answer 1

Answer:

In the given polynomial f(x)=x

2

−x−(2k+2), substitute x=−4 as shown below:

f(−4)=(−4)

2

−(−4)−(2k+2)=16+4−2k−2=18−2k

Therefore, f(−4)=18−2k.

Since it is given that x=−4 is a zero of the polynomial f(x)=x

2

−x−(2k+2), therefore f(−4)=0 that is:

18−2k=0

⇒2k=18

⇒k=

2

18

⇒k=9

Hence k=9.