Find inverse in 1 minute only

8 kg of Cu^(66) undergones radioactive decay and after 15 minutes only 1 kg remains . The half - life , in minutes , is then

find inverse using elementary operations [[6,-3],[-2,1]]

find inverse using elementary operations [[6,-3],[-2,1]]

Find the inverse using elementary row transformations: [1 1 2 3 1 1 2 3 1]

Find the inverse using elementary row transformations: [-1 1 2 1 2 3 3 1 1]

Find the inverse using elementary row transformations: [1 2 0 2 3-1 1-1 3]

Find the inverse using elementary row transformations: [2-1 3 1 2 4 3 1 1]

Find the inverse using elementary row transformations: [0 1 2 1 2 3 3 1 1]

Find the inverse using elementary row transformations: [2 0-1 5 1 0 0 1 3]

Find the inverse using elementary row transformations: [(1, 3, -2),(-3 ,0 ,1), (2, 1, 0)]