X=?
1). 4^(xy) = 2^(6x)
2). 9^(y) = 3^(xy)
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avik.ch
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1) 4^(xy) = 2^(6x)
2^2xy = 2^ 6x : 2xy = 6x : 2y=6 : y = 3, we cannot find the value of X from here. ( since degree of X is same on both side of the eq, it can take any values) - insufficient
2) 9^(y) = 3^(xy)
3 ^ 2y = 3^(xy) : 2y=xy: X=2 , sufficient.
it is B
In this kind of problem C can be directly eliminated by using this rule : the first eq is a on base 2 and second on base 3. Nothing can be solved from two equations, when the two bases( here its 2 and 3) and both are co-prime to each other. This directly eliminate C
Hope this helps !!
2^2xy = 2^ 6x : 2xy = 6x : 2y=6 : y = 3, we cannot find the value of X from here. ( since degree of X is same on both side of the eq, it can take any values) - insufficient
2) 9^(y) = 3^(xy)
3 ^ 2y = 3^(xy) : 2y=xy: X=2 , sufficient.
it is B
In this kind of problem C can be directly eliminated by using this rule : the first eq is a on base 2 and second on base 3. Nothing can be solved from two equations, when the two bases( here its 2 and 3) and both are co-prime to each other. This directly eliminate C
Hope this helps !!
