If 2x+ 1/3x=6, then the value of 3x + 1/2x will be

(a) 4
(b) 8
(c) 9
(d) 12

Anurag Mishra Professor Asked on 29th February 2016 in Maths.
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1 Answer(s)

Answer: (c) 9

Solution:-
Let the value of (3 X  + 1/2 X) be Y.
3 X + 1/2 X = Y
6 X^2 + 1 = 2 X Y
6 X^2 – 2 X Y + 1 = 0 …………………. (1) 

2 X + 1/3 X = 6
6 X^2 + 1 = 18 X
6 X^2 – 18 X + 1 = 0 ………………… (2) 

Equation  (2) subtract from equation (1), 
Then,  6 X^2 – 2 X Y + 1 – 6 X^2 + 18 X – 1 = 0
-2 X Y + 18 X = 0
– 2 X Y = – 18 X
2 Y = 18
Y = 18/2
Y = 9 

Then, the value of Y = 3 X  + 1/2 X = 9. 

Hence, the correct answer is option (c) 9. 

Anurag Mishra Professor Answered on 2nd March 2016.
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