Answer:
4
Step-by-step explanation:
7x = x² - 8
=> x² - 7x - 8 = 0
use quadratic formula:
a = 1, b = -7, c = -8
x = 
<em>(pls ignore the "A" I don't know why it's showing up)</em>
=> x = 
=> x = 
=> x = 
= 4 or 
= -5 <em>(the answer is only 4 since it's asking for the positive solution)</em>
12 customers = 9 mintues
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Divide by 3 through
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12 ÷ 3 customers = 9 ÷ 3 minutes
4 customers = 3 minutes
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Answer: She can ring up 4 customers in 3 minutes
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325-x=168
325-168=x
x=157
325-157=168
They spent $157.
<span>Ans : f(x)=xe^(-x^2/8)
differentiating by applying product rule,
f'(x)=x(e^(-x^2/8))((-2x)/8)+e^(-x^2/8)
f'(x)=e^(-x^2/8)(-x^2/4+1)
f'(x)=-1/4e^(-x^2/8)(x^2-4)
Now to find the absolute extrema of the function , that is continuous on a closed interval, we have to find the critical numbers that are in the interval and evaluate the function at the endpoints and at the critical numbers.
Now to find the critical numbers, solve for x for f'(x)=0.
-1/4e^(-x^2/8)(x^2-4)=0
x^2-4=0 , x=+-2
e^(-x^2/8)=0 ,</span>
