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2 years ago

Find f(-1) if f(x)=3x^3 + 5x^2

Mathematics

1 answer:

Reptile [31]2 years ago

7 0

Answer:

Step-by-step explanation:

f(x) = 3x^3 + 5x^2

f(-1)

so just substitute in the value -1 for x, and solve

f(-1) = 3(-1)^3 + 5(-1)^2

= 3 * -1 + 5 *1

= -3 + 5

= 2

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A vat with 700 gallons of beer contains 4% alcohol (by volume). Beer with 6% alcohol is pumped into the vat at a rate of 7 gal/m

dolphi86 [110]

Answer:

5.2%.

Step-by-step explanation:

After 1 hour (60 / 100) * 700 = 420 gallons of beer have been exchanged.

So we have 420 gallons of 6% and 280 gallons of 4% after 1 hour.

So the strength at that time = (420* 6) + 280*4) / 700

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3 years ago

Solve for x : log(3x) + log(x + 4) = log(15). Please explain it to me.

zlopas [31]

Answer:

x = 1

Explanation:

$\sf \rightarrow log(3x) + log(x + 4) = log(15)$

Rule: log(a) + log(b) = log(ab)

$\sf \rightarrow log(3x(x + 4)) = log(15)$

cancel out log on both sides

$\sf \rightarrow 3x(x + 4) = 15$

relocate constant variable

$\sf \rightarrow 3x^2 + 12x -15 = 0$

take 3 as a common factor

$\sf \rightarrow 3(x^2 + 4x -5) = 0$

divide both sides by 3

$\sf \rightarrow x^2 + 4x -5 = 0$

middle term split

$\sf \rightarrow x^2 + 5x -x-5 = 0$

factor common terms

$\sf \rightarrow x(x + 5) -1(x+5)= 0$

collect into groups

$\sf \rightarrow (x-1)(x+5)= 0$

set to zero

$\sf \rightarrow x-1 = 0 , \ x+5= 0$

relocate variables

$\sf \rightarrow x = 1, \ x = -5$

There must be a positive solution for log, so the solution is only x = 1

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1 year ago

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In a sport competition Alyssa was penalized -16 points in each of the 4 events how many points was she penalized in each event?

borishaifa [10]

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3 years ago

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3 years ago

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QveST [7]

Answer:

The area of the circle is $49\pi\ ft^{2}$

Step-by-step explanation:

we know that

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substitute the value

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3 years ago

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