This is a relatively simple half life calculation.
To go from 6 to 3 grams, 1622 years is required.
3 to 1.5 grams another 1622 years is required.
So, it undergoes exactly 2 half-lives or 3,244 years.
To see more about half-life click here:
http://www.1728.org/halflife.htm
Answer:
542 minutes
Step-by-step explanation:
currently our mean is =530
i got that by adding all the number out which equal too =2,650
and divide it by how many number there are which is 5
2,650/5=530
After some trial and error i found it
so you add 494+690+502+478+486+542=3,192
3,192/6=532
and that was our goal
so the 6th month she talked on the phone for 542 minutes
pls mark me brainliest
Answer:
$60
Step-by-step explanation:
Let's say we need t $2 bills and v $5 bills.
We need 9 more $2 bills than $5 bills, so:
t = 9 + v
We also know that the amount of money in t $2 bills is 2 * t = 2t. The amount of money in v + 9 $5 bills is 5 * (v + 9) = 5v + 45. These amounts are equal:
5v + 45 = 2t
Plug v + 9 in for t in 5v = 2t + 18:
5v = 2t + 18
5v = 2 * (9 + v) + 18
5v = 18 + 2v + 18
3v = 36
v = 12
We have 12 $5 bills, so that total cost is 12 * 5 = $60.
<em>~ an aesthetics lover</em>
Answer:
D (3,1)
Step-by-step explanation:
solving simultaneous equations
Arrange equations
2x+y=7
3x-4y=5
make y side cancell by addition by multiplying by 4 and 1 as shown
4{2x+y=7}
1{3x-4y=5}
8x+4y=28
3x-4y=5
11x=33
x=33/11=3
substitute for x=3 in 3x-4y=5
9-4y=5
4=4y
y=1
