Evaluate 1/x^-2 for x=7

Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining bismuth-210 transforms into another atom (polonium-210 in this case) each day. if you begin with 233 mg of bismuth-210, how much remains after 8 days?

Enter numbers to write 0.000328 0.000328 in scientific notation. 1 1 0.000328=3.28 × 0 . 000328 = 3 . 28 × =3.28×10 = 3 . 28 × 10

Ineed with this problem 21 show steps