Using derivatives, it is found that the x-values in which the slope belong to the interval (-1,1) are in the following interval:
(-15,-10).
<h3>What is the slope of the tangent line to a function f(x) at point x = x0?</h3>
It is given by the derivative at x = x0, that is:
.
In this problem, the function is:

Hence the derivative is:

For a slope of -1, we have that:
0.4x + 5 = -1
0.4x = -6
x = -15.
For a slope of 1, we have that:
0.4x + 5 = 1.
0.4x = -4
x = -10
Hence the interval is:
(-15,-10).
More can be learned about derivatives and tangent lines at brainly.com/question/8174665
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Answer:
x=10
Step-by-step explanation:
you know that 12x+5+6x-5=180 you can simplify the equation to 18x=180 and then you can divide both sides by 18 to get that x=10
Answer:
2:3
Step-by-step explanation:
the ratio is simplified to 2:3
10 guests = $9.50
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Find 1 guest :
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1 guest = $9.50 ÷ 10
1 guest = $0.95
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Find 75 guests :
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75 guests = $0.95 x 75
75 guests = $71.25
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Answer: It will cost $71.25 to have refreshment for 75 guests.
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I think u divide those 2 numbers not sure thou