For part (a) the answer is 400 grams for part (b) 198.63 grams and for part (c) 20 years.
<h3>What is exponential decay?</h3>
During exponential decay, a quantity falls slowly at first before rapidly decreasing. The exponential decay formula is used to calculate population decline and can also be used to calculate half-life.
We have an equation for radioactive decay:

a) Plug t = 0

m(0) = 400 grams
b) plug t = 20 years

After solving:
m(20) = 198.63 grams
c) Plug m(t) = m(0)/2 = 400/2 = 200 grams

x = 19.80 years ≈ 20 years
Thus, for part (a) the answer is 400 grams for part (b) 198.63 grams and for part (c) 20 years.
Learn more about the exponential decay here:
brainly.com/question/14355665
#SPJ1
Always remember.... x= -14
Answer:
7000
Step-by-step explanation:
lets start with 695
9 is the thousand
you check the number next to 9
less then 4 let it rest
more than 5 let it soar
something like that lol
anyways since 5 is next to the 9 we round up from 9 to the next number which is 10
so that changes the whole number to 7000
hope this makes sense!
log(3x) = log(2x-4)
taking antilog of both sides:
3x = 2x - 4
3x - 2x = -4 [subtracting 2x from both sides]
x = -4
and we're done already!