Question:
A population of insects, in thousands, can be modeled using the function
, where t is time in months. Which statement best
describes the population of insects?
A. The population is decaying at a rate of 3% each month.
B. The population is decaying at a rate of 25% each month.
C. The population is growing at a rate of 75% each month.
D. The population is growing at a rate of 97% each month.
Answer:
A. The population is decaying at a rate of 3% each month.
Step-by-step explanation:
Given

Required
True statement about the function
From the options, we can see that we are to answer the question on the basis of decay and growing rates.
An exponential form is:

Compare to 

If
, then
r represents growth rate
else,
r represents decay rate
Since b < 0.97:





Answer:
Option.B
Step-by-step explanation:
Its because if you add these two angles you get a supplementary angle or 180°
Using this we can form an equation to find the value of x.
(Hope this answer helps :))
(And is this question from Khan Academy?)
<u><em>Answer:</em></u>
You should multiply the expression by 
<u><em>Explanation:</em></u>
To rationalize any expression, you must multiply it by its conjugate. A conjugate is defined as a similar expression to the original one but with an opposite sign
<u>This means that:</u>
The conjugate of a + b would be a - b
Now, the given expression is 
<u>Consider the denominator:</u>
From the above, we can conclude that the conjugate of
is 
<u>And, remember that</u> we need to keep the value of the expression unchanged. This means that we must multiply both the numerator and the denominator by the same value
<u>Therefore:</u>
You should multiply the expression by
in order to rationalize the denominator
Hope this helps :)