The remaining amounts, in kilograms, of two radioactive substances after x years are modelled by the expressions below.
A: (0.9)ˣ⁺¹
B: (0.6)ˣ
Approximately how many years will it take for the remaining amount of substance A to equal 4 times the remaining amount of substance B?
0.260
0.611
1.506
3.679