In the last lecture of this semester, when we were studying the effect of the change in P, (i.e. dP), the equation -Pdx*-P,dy*=x*dP+y*dP,- dB reduced to -Pdx-P,dy=x* dP, and when we compensated for the consumer's real income loss by dropping the term x*dP,, the equation became -Pdx*-P,dy* = 0. Show that this result can also be obtained alternatively from a compensation procedure whereby we keep the consumer's optimal utility level U* unchanged.