Answer:
The rate of decrease is 8%
Step-by-step explanation:
we know that
The general equation for the radioactive decay can be written as:

where
a is the amount in kilograms after time t.
a_0 is the original amount of the substance or y-intercept of the function
r is the decay rate, written in decimals.
t is the time
In this problem we have

so

solve for r

Convert to percentage

Answer:
9 lb 3 oz
Step-by-step explanation:
(3 + 5) lb + (9 + 10) oz
8 lb + 19 oz
16 oz = 1 lb
(8 + 1) lb + (19 - 16) ox
9 lb 3 oz
Answer: 5 brownies
Step-by-step explanation:
cookies = 5 x $0.50 = $2.5
$15 - $2.5 = $12.5
$12.5 divided by $2.25 = $5.555
so at the most ella can buy 5 brownies if she buys 5 cookies
So k=katie's' age
m=mara's age
k is 2 times as old as m
k=2m
sum is 24
add means sum
k+m=24
so we have
k+m=24 and
k=2m
subsitute
2m+m=24
add
3m=24
divide both sides by 3
m=8
subsitute again
k=2m
k=2(8)
k=16
katie=16
mara=8