A sample of a radioactive isotope had an initial mass of 470 mg in the year 2000 and decays exponentially over time. A measurement in the year 2003 found that the sample's mass had decayed to 260 mg. What would be the expected mass of the sample in the year 2013, to the nearest whole number?

you have 6 equal triangles, find the area of one of them (b*h/2) and multiply by 6

(8*4: 2)*6 =

32 cm² is your answer

hi there!

not proportional because the 42 does not go into 120 and 3 does not go into 8.

correct proportion: $40/1 ticket.

the reason i say this is because 40/1 is simplified and it evenly goes into 120/3.

hope this : )