All categories

3 years ago

Evaluate 3x2 - 1 when x = 2.

Mathematics

1 answer:

Shalnov [3]3 years ago

4 0

Answer:C or 11

Step-by-step explanation:

3x²-1

First you insert x... which is 2

3(2)²-1

then you square the 2. (multiply it by itself)

3(4)-1

Then you multiply 3 by 4 to get 12

12-1

And then you subtract for your answer

You might be interested in

Solve the system of linear equations in two variables by elimination or substitution.

taurus [48]

Answer:

( $\frac{1}{2}$ , 0 )

Step-by-step explanation:

Given the 2 equations

4x + 3y = 2 → (1)

2x - 3y = 1 → (2)

Adding (1) and (2) term by term will eliminate the y- term, that is

6x = 3 ( divide both sides by 6 )

x = $\frac{3}{6}$ = $\frac{1}{2}$

Substitute x = $\frac{1}{2}$ into either of the 2 equations and evaluate for y

Substituting into (1)

4( $\frac{1}{2}$ ) + 3y = 2

2 + 3y = 2 ( subtract 2 from both sides )

3y = 0 ⇒ y = 0

Solution is ( $\frac{1}{2}$ , 0 )

8 0

3 years ago

Suppose you have a light bulb that emits 50 watts of visible light. (Note: This is not the case for a standard 50-watt light bul

natali 33 [55]

Answer:

0.049168726 light-years

Step-by-step explanation:

The apparent brightness of a star is

$\bf B=\displaystyle\frac{L}{4\pi d^2}$

where

<em>L = luminosity of the star (related to the Sun) </em>

<em>d = distance in ly (light-years) </em>

The luminosity of Alpha Centauri A is 1.519 and its distance is 4.37 ly.

Hence the apparent brightness of Alpha Centauri A is

$\bf B=\displaystyle\frac{1.519}{4\pi (4.37)^2}=0.006329728$

According to the inverse square law for light intensity

$\bf \displaystyle\frac{I_1}{I_2}=\displaystyle\frac{d_2^2}{d_1^2}$

where

$\bf I_1=$ light intensity at distance $\bf d_1$

$\bf I_2=$ light intensity at distance $\bf d_2$

Let $\bf d_2$ be the distance we would have to place the 50-watt bulb, then replacing in the formula

$\bf \displaystyle\frac{0.006329728}{50}=\displaystyle\frac{d_2^2}{(4.37)^2}\Rightarrow\\\\\Rightarrow d_2^2=\displaystyle\frac{0.006329728*(4.37)^2}{50}\Rightarrow d_2^2=0.002417564\Rightarrow\\\\\Rightarrow d_2=\sqrt{0.002417564}=\boxed{0.049168726\;ly}$

Remark: It is worth noticing that Alpha Centauri A, though is the nearest star to the Sun, is not visible to the naked eye.

7 0

3 years ago

Which choice most effectively combines the

pav-90 [236]

The choice that combines the given sentences most effectively is: Option C : furnished: their.

<h3>What is sentence correction?</h3>

Sentence correction or sentence improvement is a type of grammatical practice where a sentence is given with a word or a phrase that requires grammatical changes or improvement.

Now, here in the given sentence:

"The plainer rooms are more sparsely <u>furnished. Their</u> architectural features, furnishings, and decorations are just as true to the periods they represent",

The most suitable choice, by sentence correction, to combine the two sentences will be: Furnished: their (option C).

To learn more about sentence correction, refer to the link: brainly.com/question/14632568

#SPJ4

7 0

2 years ago

Lee scored 91 points on a math testOn the next test, she scored 13 fewer pointsOn the third test, she scored 92What is the diffe

max2010maxim [7]

Answer:

14 points

Step-by-step explanation:

The second test Lee did was 13 points fewer than the first test, which was 91 points, so the second test's score is 91 - 13 = 78 points.

The third test had the score of 92, so this is the highest score, and the lowest score is the second one: 78 points.

The difference between Lee's highest and lowest scores is:

92 - 78 = 14 points

4 0

3 years ago

Can someone please help and thank you:)

polet [3.4K]

Answer:

F: 3(3.4) = 10.2- FALSE

G: 3.9(3.4) = 13.26- FALSE

H: 5(3.4) = 17- FALSE

J: 2.5(3.4) =8.5- TRUE

J is true.

Let me know if this helps!

5 0

3 years ago