Answer:
The exponential function for the US population is:
Step-by-step explanation:
Let be supposed that US population can be modelled by means of the following exponential function:
Where:
- Time, measured in years. Where t = 0 for 1970.
- Initial population, in millions inhabitants.
- Exponential rate constant, in years.
- Population, in millions inhabitants.
Each constant is found hereafter:
A
B
The exponential function for the US population is:
f(x) = -5x^2 - x + 20;
f(3) = -5*3^2 - 3 + 20 = -5*9 - 3 + 20 = -45 - 3 + 20 = -28;
Answer:
11a + 3
Step-by-step explanation:
Step 1 : 8a + 3 - 5a - 2a
error => - 5a
8a - (- 3 - 5a) - 2a =
= 8a + 3 + 5a - 2a
= (8a + 5a - 2a) + 3
= 11a + 3
1. The formula for calculate the area of a rectangle, is:
A=LxW
A is the area of the rectangle
L is the length of the rectangle.
W is the widht of the rectangle
2. You have that:
-The<span> rectangular Corn Hole area has a width of 5 feet and a length of 10 feet, so:
L1=10 feet
W1=5 feet
- When</span> a uniform amount is added to each side (x), the area is increased to 84 feet². Then, you have a different length (L2) and a different width (W2):
3. The new length is:<span>
L2=L1+x+x
L2=L1+2x
L2=10+2x
4. The new width is:
W2=W1+x+x
W2=W1+2x
W2=5+2x
5. The new area is:
A2=84 feet</span>²<span>
6. Then, you have:
A=LxW
84</span>=(10+2x)(<span>5+2x)
7. When you apply the distributive property, you obtain a quadratic equation:
4x</span>²+30x-34=0
<span>
8. You can solve with by applyin the quadratic formula:
x=(-b±√(b^2-4ac))/2a
a=4
b=30
c=-34
9. Then, the answer is:
x=1 feet
</span><span>
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