Answer:
The function that represents the mass of the sample after t days is
.
The percentage rate of change per hour is of -2.46%.
Step-by-step explanation:
Exponential amount of decay:
The exponential amount of decay for an amount of a substance after t days is given by:

In which A(0) is the initial amount, and r is the decay rate, as a decimal.
Element X is a radioactive isotope such that its mass decreases by 59% every day. The experiments starts out with 390 grams of Element X.
This means, respectively, that 
So



The function that represents the mass of the sample after t days is
.
Hourly rate of change:
Decreases by 59% every day, which means that for 24 hours, the rate of change is of -59%. So
-59%/24 = -2.46%
The percentage rate of change per hour is of -2.46%.
500cal=1lb
1000cal=2lbs
2x5=10
1000x5=5000
Answer: 10 banana splits
That they are the exact same shape. Some of the sides will be longer and shorter than the other figure, but same shape.
1) Striangle = 1/2 * (12-8) * 4 = 1/2 * 4 * 4 = 8 km^2
2) Srectangle = 4 * 8 = 32 km^2
3) Sfigure = 8 + 32 = 40 km^2
Number C
Answer:
a. A minimum of 300
Step-by-step explanation:
If her bill is $142 then it is a sum of the flat rate plus the money she pays for all the smses she sent. As an equation, it can be expressed this way
106 + 0.12x = 142 where x is the number of smses
0.12x = 36
x = 300 smses
So if we were told that she pays $142 per month, we'd know that she sends 300 smses. But we are told she pays AT LEAST $142 so there is a possibility that she sends even more than 300 smses