Given: u=x^0.3y^0.7 utility function I=2px+3py budget constrain Apply shephard lemma.

 I agree with MrBenard answers, thanks for the invitation. 

agree with expert answers                .

Shephard's Lemma is a major result in microeconomics having applications in the theory of the firm and in consumer choice. Lemma  states that if indifference curves of the expenditure or cost function are convex, then the cost minimizing point of a given good( ) with price is unique.

In consumer theory, Shephard's lemma states that ;the demand for a particular good i  for a given level of utility u and given prices p equals the derivatives of the expenditure function with respect to the price of the relevant good.

if I=2px+3py,is the expenditure function then the derivative with respect to price  p will  be;

di/dp=2x+ 3y...but from the given statement its not clear what is required , I therefore leave the rest to other experts to figure it out, ,Thank you.  

Thank you for the invitation,

I leave the answer for the experts in microeconomics.

I apologize for the answer I do not know, I leave the answer to experts specialists in this field that's not my specialty field