X+(y+z) is equal to saying (x+y)+z
This is called the cumulative property when order doesn’t matter or doesn’t change the equation. As in 1+2 is the same as 2+1. No matter which way we get the same answer. This only works with multiplication and addition though. Hope this helps. Any questions please just ask!! Thank you so much!!
Answer: no they are not
Step-by-step explanation:

It tells you that over these intervals the balloon is going at a constant speed.
Answer:
I guess they subtracted a 110 from -110 instead of subtracting from 360
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%.