Suppose a laboratory has a 31 g sample of polonium-210. the half-life of polonium-210 is about 138 days. how many half-lives of polonium-210 occur in 966 days? how much polonium is in the sample 966 days later?

I'll give brainliest if you answer right : )

Aplane flies around trip to philadelphia it flies to philadelphia at 220 miles per hour and back home with a tailwind at 280 miles per hour if the total trip takes 6.5 hours how many miles does the plane fly round trip

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b