X(x-1)(x^2+4)=(x^2-x)(x^2+4)=(x^4)+(4x^2)-(x^3)-(4x)=(x^4)-x(x^2+4)+(4x^2)
Answer: You need a grade of 78 on the final exam to earn a final grade average of at least 87 in each grading system.
Step-by-step explanation:
(85 + 90 + 95 + x)÷ 4 =87
Simplify:
(270 + x) ÷ 4 = 87
Rearrange:
(x + 270) ÷ 4 = 87
Multiply terms to Reduce:
4((x + 270) ÷ 4) = 4 * 87
Cancel Multiplied terms in Denominator:
x + 270 = 4 * 87
Multiply:
x + 270 = 348
Subtract 270 on both sides of the equation:
x + 270 - 270 = 348 - 270
Simplify:
x = 78
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
![p(t) = 1.75(0.97)^t](https://tex.z-dn.net/?f=p%28t%29%20%3D%201.75%280.97%29%5Et)
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:
![y=ab^x](https://tex.z-dn.net/?f=y%3Dab%5Ex)
Compare to ![p(t) = 1.75(0.97)^t](https://tex.z-dn.net/?f=p%28t%29%20%3D%201.75%280.97%29%5Et)
![b= 0.97\\](https://tex.z-dn.net/?f=b%3D%200.97%5C%5C)
If
, then
r represents growth rate
else,
r represents decay rate
Since b < 0.97:
![0.97= 1-r](https://tex.z-dn.net/?f=0.97%3D%201-r)
![r = 1 - 0.97](https://tex.z-dn.net/?f=r%20%3D%201%20-%200.97)
![r = 0.03](https://tex.z-dn.net/?f=r%20%3D%200.03)
![r = 3\%](https://tex.z-dn.net/?f=r%20%3D%203%5C%25)
![r = 0.03](https://tex.z-dn.net/?f=r%20%3D%200.03)
The slope is negative two (-2)
Positive because it does not go less than 0.