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%.
35x – 13 x = x – 1
⇒ 22 x = x - 1
⇒ 22x - x = -1
⇒ 21x = -1
⇒ x = -1/21
Thus,the value of x is -1/21
Answer:
x = 11
Step-by-step explanation:
Consecutive means in a row
Let x be the first integer
x+1 is the second
x+2 is the third
x+3 is the 4th
The sum is 50
x+ x+1 + x+2 + x+3 = 50
Combine like terms
4x+6 = 50
Subtract 6 from each side
4x+6-6 = 50-6
4x = 44
Divide each side by 4
4x/4 = 44/4
x = 11
B)40 because (4)*50/5 is (4)*10