A laboratory that uses radioactive substances received a shipment of 122 g of bismuth-210. Only 6.64 g of the bismuth-210 remained 21.0 days later. Determine the half-life of bismuth-210 algebraically using logarithms, to the nearest tenth of a day. The half-life equation is ID: A A = 4₂ (²) where A represents the amount of the substance remaining, Ao represents the initial amount of the substance, t represents the time, and h represents the time at which only half of the substance remains.​