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if 2x^(2) + 4x - k = 0 is same as (x-5) ...

if `2x^(2) + 4x - k = 0` is same as `(x-5) (x+k/10) = 0`, then find the value of k.

A

100

B

90

C

70

D

35

Text Solution

Verified by Experts

The correct Answer is:
C
`2x^(2) + 4x - k = 0 " "(1)`
`:. rArr (x-5)` is a factor of Eq. (1).
`rArr x - 5 = 0 rArr x = 5`
`:. 2(5)^(2)+ 4(5) - k = 0`
`50+20 - k = 0`
`:. k = 70`.
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