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If A={x in R//x^(2)+5|x|+6=0} then n(A)=...

If `A={x in R//x^(2)+5|x|+6=0}` then n(A)= . . .

A

2

B

0

C

1

D

4

Text Solution

Verified by Experts

The correct Answer is:
D
We have, `x^(2)-5absx+6=0`
`!x^(2)-3absx-2absx+6=0`
`!absx(absx-3)-2(absx-3)=0`
`!(absx-2)(absx-3)=0`
`!absx-2=0` or `absx-3=0`
`!x=-2,2` or `x=-3,3`
`therefore` n(A)=4
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