question_answer

If \[\frac{\mathbf{2}}{\mathbf{x}}\mathbf{+}\frac{\mathbf{3}}{\mathbf{y}}\mathbf{=}\frac{\mathbf{9}}{\mathbf{xy}}\] and \[\frac{4}{\mathbf{x}}\mathbf{+}\frac{9}{\mathbf{y}}\mathbf{=}\frac{21}{\mathbf{xy}}\], where, \[x\ne 0\]and \[y\ne 0\], then what is the value of \[\mathbf{x}+\mathbf{y}\]?

A)  2                                

B)  3

C)  4 

D)  8