Number of roots of equation |x{|^2} - 7|x| + 12 = 0 is

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4-2.Quadratic Equations and Inequations

easy

The number of roots of the equation $|x{|^2} - 7|x| + 12 = 0$ is

A

$1$

B

$2$

C

$3$

D

$4$

Solution

(d) The equation $(|x| – 4)(|x| – 3) = 0$

==> $|x| = 4\,\, \Rightarrow x = \pm 4$ ==> $|x| = 3\,\, \Rightarrow x = \pm 3$.

Standard 11

Mathematics

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