If a + 3b = 12 and ab = 9, then the value of (a - 3b) is:
A. 4
B. 7
C. 6
D. 9
Answer: Option C
Solution (By Examveda Team)
If a + 3b = 12ab = 9
(a - 3b)2 = a2 + 9b2 - 6ab
(a - 3b)2 = (a + 3b)2 - 12ab
(a - 3b)2 = 144 - 108
(a - 3b)2 = 36
(a - 3b) = 6
This Question Belongs to Arithmetic Ability >> Algebra
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