Hi!

I've got the following utility function:

prices are

is the price of good 1

is the price of good 2

is the quantity of good 1

is the quantity of good 2

The budget costraint is:

Now, we know that we have equilibrium when we have

because weighted marginal utilities are equal.

Ok, now this is where i get stuck! The book "says" that

My question is: why are equal to and equal to equal to ?Quote:

with our data, we have:

and

Thank you in advance!