Respuesta :
The required expression is 100 - 0.2w
Step-by-step explanation:
Given,
Amount of radioactive substance = 100 mg
The substance decreases by 20% each week.
To find the remaining amount of the in w weeks.
Now,
Each week 20% = 0.2 of the substance will be decreased.
So, in w weeks 0.2×w of the the substance will be decreased.
Hence,
The remaining substance = 100 - 0.2w
Answer:
It is the difference between the initial amount and the percent decrease.
Step-by-step explanation:
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