Express 8cm as fraction of 2metres.​

Suppose a laboratory has a 30 g sample of polonium-210. the half-life of polonium-210 is about 138 days how many half-lives of polonium-210 occur in 1104 days? how much polonium is in the sample 1104 days later? 9; 0.06 g 8; 0.12 g 8; 2,070 g

1/2+1/6-3/4 simplify the given expression leaving the answer in improper fraction form.

Can anyone explain to me how to do this? anything will .