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3 years ago

If f(x) = 8x2-5, what is f(-1)

Mathematics

2 answers:

Klio2033 [76]3 years ago

5 0

Step-by-step explanation:

Remember math is a language

f(x) : A function of x where x can be <em>any</em><em> </em>number including a number you choose

when you see f(-1), this tells you what the function is at <em>this</em> given x value. So you substitute - 1 wherever you see x

8(-1)2 - 5

Nikolay [14]3 years ago

4 0

Answer:3

Step-by-step explanation:

Simply plug in -1 for anywhere you see x in the equation so...

8(-1)^2-5

8(1)-5

8-5

Hope this helps

Read more about expressions at:

brainly.com/question/723406

#SPJ1

8 0

2 years ago

Rick buys 3 CDs and 5 video games. The cost of one video game is $12.00 more than the cost of one CD. If Rick spends $164.00, wh

Dmitry [639]

Step-by-step explanation:

x = price per video game

y = price per CD

164 = 5x + 3y

and then we know

x = y + 12

now we can use this as substitute in the first equation :

164 = 5(y + 12) + 3y = 5y + 60 + 3y = 8y + 60

104 = 8y

y = $13

x = y + 12 = 13 + 12 = $25

so, each CD costs $13.

4 0

3 years ago

Air pressure may be represented as a function of height (in meters) above the

denis-greek [22]

Answer: OPTION C.

Step-by-step explanation:

<h3> The complete exercise is: "Air pressure may be represented as a function of height (in meters) above the surface of the Earth, as shown below:</h3><h3> $P(h) =P_0e^{-0.00012h}$ </h3><h3> In this function $P_o$ is the air pressure at the surface of the earth, and $h$ is the height above the surface of the Earth, measured in meters. At what height will the air pressure equal 50% of the air pressure at the surface of the Earth"</h3><h3></h3>

Given the following function:

$P(h) =P_0e^{-0.00012h}$

In order to calculate at what height the air pressure will be equal 50% of the air pressure at the surface of the Earth, you can follow these steps:

1. You need to substitute $P(h)=0.5P_o$ into the function:

$0.5P_o=P_0e^{-0.00012h}$

2. Finally, you must solve for $h$ .

Remember the following property of logarithms:

$ln(b)^a=a*ln(b)\\\\ln(e)=1$

Then, you get this result:

$0.5P_o=\frac{P_o}{e^{0.00012h}}\\\\(0.5P_o)(e^{0.00012h})=P_o\\\\e^{0.00012h}=\frac{P_o}{0.5P_o}\\\\ln(e)^{0.00012h}=ln(2)\\\\0.00012h*1=ln(2)\\\\h=\frac{ln(2)}{0.00012}\\\\h=5576.2$

7 0

3 years ago

A yard cleanup service charges a $345 fee plus $16.25 per hour. Another cleanup service charges a $213 fee plus $24.50 per hour.

Thepotemich [5.8K]

The time for the job for which the two company are the same is 16

<h3>How to form the equation and find the cost?</h3>

A yard cleanup service charges a $345 fee plus $16.25 per hour. Therefore,

using linear equation,

y = mx + c

where

y = total cost
x = time

Therefore,

y = 345 + 16.25x

Another cleanup service charges a $213 fee plus $24.50 per hour. Therefore,

y = 213 + 24.50x

Hence, the time when both cost are the same is as follows;

213 + 24.50x = 345 + 16.25x

213 - 345 = 16.25x - 24.50x

-132 = -8.25x

x = 132 / 8.25

x = 16

learn more on equation here: brainly.com/question/2072580

4 0

2 years ago