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3 years ago

Find the percent change from 84 to 63.

Mathematics

2 answers:

REY [17]3 years ago

3 0

Answer:

-25%

20 characters

oksian1 [2.3K]3 years ago

3 0

so the difference is 84 - 63 = 21.

if we take 84 to be the 100%, what is 21 off of it in percentage?

$\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 84&100\\ 21&x \end{array}\implies \cfrac{84}{21}=\cfrac{100}{x}\implies 4=\cfrac{100}{x}\implies 4x=100 \\\\\\ x=\cfrac{100}{4}\implies x=25$

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Tom [10]

Answer:

I found the table by an online search (it is below)

Sally has $7 to spend in candy.

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In the table, we have the following combinations.

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3*$1.50 + 3*$0.75 + 4*$0.25 = $7.75 (she can not buy this)

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3*$1.50 + 4*$0.25 = $5.50 (she can buy this)

c) 1 chocolate bar, 5 lollipops and 2 gumballs, the price is:

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3 years ago

Prove that the equation <br> x^3 + x + 3 = 0 <br> has exactly one real root on the interval [-2,-1].

maw [93]

Answer:

the value of the function changes sign in the interval
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Step-by-step explanation:

All polynomial functions are continuous, so we know from the intermediate value theorem that if the expression on the left changes sign in the interval [-2, 1] then there will be a zero in that interval. If the function is monotonic in the interval, there can only be one zero.

a) For f(x) = x^3 +x +3 = (x^2 +1)x +3, the values at the ends of the interval are ...

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f'(x) = 3x^2 +1

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4 years ago

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