243^-y=(1/243)^3y*9^-2y a.) y=-1 b.) y=0 c.) y=1 d.) no solution

Me what is the value of x? showing work would be appreciated - ! : )

Which choice represents the sample space ,s for this event

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days