Q25 of 44 Page 4

Using properties of determinants, solve the following for x:

(CBSE 2011)

Given,



Applying C2→ C2 – 2C1 and C3→ C3 – 3C1


⇒


Applying R2→ R2 + R1 and R3→ R3 + 11R1


⇒


Expanding about the second column-


∴ (-1)


⇒ (-18)(2x – 6) + 2(12x – 30) = 0


⇒ -36x + 24x +108 – 60 = 0


⇒ 12x = 48


∴ x = 48/12 = 4

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