Answer:
The first one
Step-by-step explanation:
Answer:
The differential equation is 
Step-by-step explanation:
Differential equation for the rate of change in radiation level:
Radiation level is R.
Rate of change indicates that the radiation level R varies in function of time t, which mathematically means that we have:

After the reactor is shut down, the radiation from the nitrogen-17 decreases in such a way that the rate of change in the radiation level is directly proportional to the radiation level.
Rate of change is k. Decreases means that k is negative. Proportional to the radiation level of R means that -k multiplies R. So the differential equation is:

First, lets convert them into multipliers:
The multiplier for a:
25% increase = 1.25
40% decrease = 0.6
40% increase = 1.4
Now to work out the overall percentage change, we just times all of the multipliers together, and convert it back to a percentage:
1.25 x 0.6 x 1.4 = 1.05
So the overall multiplier is 1.05
And a multiplier of 1.05 = a <u>5% increase</u>.
That means that the percentage change is + 5%
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Answer:
The percentage change in shares from the start of 2013 to the end of 2015 is:
+ 5%
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Note: if you haven't been taught multipliers - then ask and I'll try my best to explain!
A is addition
b is subtraction
c is division
Answer:
y = 7 - 2x/3
Step-by-step explanation:
Make the y alone, so 3y = -2x+21
Divide everything else by 3, so y = -2x/3 +7
You end with the answer of y= 7-2x+3