HELP ASAP Element X is a radioactive isotope such that every 20 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 770 grams, how long would it be until the mass of the sample reached 400 grams, to the nearest tenth of a year?

4038

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pleaze mark brainliest!

this is a very good question

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i got a hair cut today from my mom not to flex just to flex kim jon un is one rad fellow i'd say you'd need to take the hairline in kinda like a box shape like someone rammed a lego brick into your head. from there you really need to take the top up keeping with that boxy aesthetic, finally coat the whole thing with gel if your country economics are failing or whatever you can just coat it with the starving children's food rations. about 5 orphans per strand is a good ratio. good luck with the fresh cut my dude

2

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answer is (b.

164 ft2)

a base  

18

b base  

7

h height  

8