Given the definitions of f(x) and g(x) below, find the value of g(f(-1)).
f(x) = -4x – 7
g(x) = x² + 7x – 2
​

Answer:

a. 135 g

b. 60.6 min

Step-by-step explanation:

a. What mass of Cu(s) is electroplated by running 28.5 A of current through a Cu2+ (aq) solution for 4.00 h? Express your answer to three significant figures and include the appropriate units.

The chemical equation for the reaction is given below

Cu²⁺(aq) + 2e⁻ → Cu(s)

We find the number of moles of Cu that are deposited from

nF = It where n = number of moles of electrons, F = Faraday's constant = 96485 C/mol, I = current = 28.5 A and t = time = 4.00 h = 4.00 × 60 min/h × 60 s/min = ‭14,400‬ s

So, n = It/F = 28.5 A × ‭14,400‬ s/96485 C/mol = ‭410,400‬ C/96485 C/mol = 4.254 mol

Since 2 moles of electrons deposits 1 mol of Cu, then 4.254 mol of electrons deposits 4.254 mol × 1 mol of Cu/2 mol = 2.127 mol of Cu

Now, number of moles of Cu = n' = m/M where m = mass of copper and M = molar mass of Cu = 63.546 g/mol

So, m = n'M

= 2.127 mol × 63.546 g/mol

= 135.15 g

≅ 135 g to 3 significant figures

b. How many minutes will it take to electroplate 37.1 g of gold by running 5.00 A of current through a solution of Au+(aq)?

The chemical equation for the reaction is given below

Au⁺(aq) + e⁻ → Au(s)

We need to find the number of moles of Au in 37.1 g

So, number of moles of Au = n = m/M where m = mass of gold = 37.1 g and M = molar mass of Au = 196.97 g/mol

So, n = m/M = 37.1 g/196.97 g/mol = 0.188 mol

Since 1 mol of Au is deposited  by 1 moles of electrons, then 0.188 mol of Au deposits 0.188 mol of Au × 1 mol of electrons/1 mol of Au = 0.188 mol of electrons

We find the time it takes to deposit 0.188 mol of electrons that are deposited from

nF = It where n = number of moles of electrons, F = Faraday's constant = 96485 C/mol, I = current = 5.00 A and t = time

So, t = nF/It

= 0.188 mol × 96485 C/mol ÷ 5.00 A

= ‭18173.30‬ C/5.00 A

= 3634.66 s

= 3634.66 s × 1min/60 s

= 60.58 min

≅ 60.6 min to 3 significant figures

Answer:

number 3

Step-by-step explanation:

thats my calcue

Answer:

[tex]P(Green\ or\ Red) = 0.30[/tex]

Step-by-step explanation:

Given

[tex]White = 40[/tex]

[tex]Green = 24[/tex]

[tex]Red = 12[/tex]

[tex]Yellow = 24[/tex]

[tex]Blue = 20[/tex]

Required

[tex]P(Green\ or\ Red)[/tex]

The total numbe of candy is:

[tex]Total = 40 + 24 + 12 + 24 + 20[/tex]

[tex]Total = 120[/tex]

This probability is calculated as:

[tex]P(Green\ or\ Red) = P(Green) + P(Red)[/tex]

For each, we have:

[tex]P(Green\ or\ Red) = \frac{Green}{Total} + \frac{Red}{Total}[/tex]

Take LCM

[tex]P(Green\ or\ Red) = \frac{Green+Red}{Total}[/tex]

[tex]P(Green\ or\ Red) = \frac{24+12}{120}[/tex]

[tex]P(Green\ or\ Red) = \frac{36}{120}[/tex]

[tex]P(Green\ or\ Red) = 0.30[/tex]

Answer:

18

Step-by-step explanation:

=============================================================

Explanation:

Multiply out those values mentioned to get the final answer: 3*3*2 = 9*2 = 18.

There are 18 different outfit combos.

---------------

Further explanation (optional section):

Let's say we only worried about the sweaters and shoes, and for now there's only one color for the skirt. We have 3 colors for the sweaters and 2 for the shoes. Imagine a table with 3 rows and 2 columns. Each row is a different color for the sweater and each column is a different color for the shoe. There are 3*2 = 6 cells inside the table. Each cell is a different outfit.

For instance, we could have R = red sweater and G = gold shoe. Then that means RG = red sweater + gold shoe outfit. So we'd have RG as one of the cells of this 6 cell table.

Now imagine that we laid out a table that is 6 by 3. The 6 is from the 6 outfits calculated earlier, and the 3 is now accounting for the colors of the skirts. We'd then have 6*3 = 18 combos total. Again, each cell inside the table represents a different outfit combo.

Answer:

150°

Step-by-step explanation:

We know each angle in a equilateral triangle is 60° and that of a rectangle is 90° . So ,

[tex]\implies \angle ABC = \angle DBC + \angle ABD \\\\\implies \angle ABC = 90^o + 60^o \\\\\implies \boxed{\boxed{ \angle ABC = 150^o }}[/tex]

Answer:

4

Step-by-step explanation:

Step-by-step explanation:

Bigger -smaller

hope it is helpful to you

Answer:

Step-by-step explanation:

D beause less then 5 that means it gose down the grid

Answer:

x = 3

Step-by-step explanation:

Once again we want to use the relationship stated earlier

Where A * B = C * D

Once again imagine that the segments in the given problem have letters

A = x

B = 12

C = x + 1

D = 9

Now we create an equation using the relationship

12 * x = 9(x+1)

now we solve using basic algebra

step 1 distribute the 9 to the x and the 1

9 * x = 9x

9 * 1 = 9

now we have 12x = 9x + 9

step 2 subtract 9x from each side

12x - 9x = 3x

9x - 9x cancels out

now we have 3x = 9

step 3 divide each side by 3

3x/3=x

9/3=3

we're left with x = 3

Answer:

x = 3 / C. 3

Step-by-step explanation:

Hope this helps

Answer:

Ok so first he bought the road and pancakes with means he speant 134.85 dollars which mean he out himself in the negatives after he bought the his items

Answer:

Calm down jamal don't go pulling out the nine

Step-by-step explanation:

this is just a joke

Answer:

Here, the test statistics ( 20.951 ) is greater than the critical value ( 7.815 )

Therefore, we reject H₀ at 0.05 level of significance.

Hence, there is significant evidence to support the claim that In this community, vehicle ownership distribution is NOT like that of all U.S household

Step-by-step explanation:

Given the data in the question;

Number of vehicle owned                 Number of households

0                                                             20

1                                                              35

2                                                             23

3 or more                                               22

Total ( n )                                               100

so

Null hypothesis           H₀ : In this community, vehicle ownership distribution is like that of all U.S household

Alternative hypothesis Hₐ : In this community, vehicle ownership distribution is NOT like that of all U.S household

Also given that, ∝ = 0.05

Now, we compute the test statistics;

x² = ∑[ ( O[tex]_i[/tex] - E[tex]_i[/tex] ) / E[tex]_i[/tex] ]

where E[tex]_i[/tex] is expected frequency and O[tex]_i[/tex] is observed frequency.

so we make our table for chi square test statistics

No. of                 O[tex]_i[/tex]            P                E[tex]_i[/tex]            (O[tex]_i[/tex] - E[tex]_i[/tex])²             (O[tex]_i[/tex] - E[tex]_i[/tex])²/E[tex]_i[/tex]

Vehicle                                              (n×P)

owned

0                        20         0.087          8.7            127.69                 14.677

1                         35         0.331           33.1            3.61                     0.109

2                        23         0.381           38.1           228.01                 5.985

3 or more          22         0.201          20.1           3.61                      0.180

Total                  100                           100                                        20.951

hence, x² = 20.951

Now, degree of freedom df = k - 1 = 4 - 1 = 3

From Chi-Square critical value table; ( right tailed test ) for ∝ = 0.05

[tex]x_{0.05, 3[/tex] = 7.815

Decision Rule

Reject H₀ if x² is greater than xₐ².

Here, the test statistics ( 20.951 ) is greater than the critical value ( 7.815 )

Therefore, we reject H₀ at 0.05 level of significance.

Hence, there is significant evidence to support the claim that In this community, vehicle ownership distribution is NOT like that of all U.S household

Answer: [tex]\dfrac{1}{52}[/tex]

Step-by-step explanation:

Given

We need to choose 6 of clubs that's also a red

A deck contains 13 cards of clubs, and 6 of clubs is the only red card i.e. favorable outcome is 1 out of 52 cards

Probability is the ratio of favorable to the total outcomes

[tex]\Rightarrow P=\dfrac{1}{52}[/tex]

Answer:

Step-by-step explanation:

we need the arc length formula . it's Arc length = 2πr (θ/360)

Arc length = 2π5 (144/360)

Arc length = 12.56637 cm  

Answer:

Step-by-step explanation:

             80% of 25 = 5

because 10% of 25 = 2.5

and then       10 x 8 = 80

so                2.5 x 8 = 20

                  25 - 20 = 5

therefore, the percentage change is 80%

GIVE BRAINLIEST

hope this helped,

-cheesetoasty

Answer: c

Step-by-step explanation:

Answer:

<3=105°

Step-by-step explanation:

The angle directly to the right of the 75° angle is 105°, as the angles along a straight line add to 180.

<3=105° because they are corresponding angles

Answer:

Solution given:

<3+75=180[co- interior angle]

<3=180°-75°=105°

<3=105°

Step-by-step explanation:

work is on the paper for you, somthing that might help you with your future with math is PEMDAS always do exponents first when it's an equation like your first, second, and third question. I hope this helped.

Answer:

-3 I believe

Step-by-step explanation:

why dose the answer have to be 20+ letters

Answer:

-3

Step-by-step explanation:

To find y, plug in -12 for x in the y=1/4x equation. Multiply -12 by 1/4 (or divide -12 by 4) and you get -3.

Answer:

1.

mean= 84.6

median=84

mode=84

2.

mean=10.14

median=9

mode=9

3.

mean=22.3

median=21

mode=phi

Step-by-step explanation:

mean: the sum of of the quantities by their number

median: the median value after rearranging the values

mode: the value that occurs most frequently

in the second question

mean = (8+9+9+9+9+10+11+15)/8

median(even number) =(9+9)/2=9

mode=9

Answer:

for data set 1

1.mean-84.6

2.median-(84+84)/2 = 84

3.mode-84

for data set 2

1.mean-9.25

2.median-(9+9)/2 = 9

3.mode-9

for data set 3

1.mean-22.3

2.median-21

3.mode-no mode with this data set

hope this helped!!

Q) What percentage of sudents who passed the test completed the review sheet

A)

19/27*100

=70.37%

Nearest 10th of a percent

=70%

Answer:

-4-2/-1-1=-6/-2= 3

So the answer is 3

Answer:

2,1,0 is the sequence of its terms

Answer:

3

Step-by-step explanation:

1 hour = 60 minutes.

1/4 of an hour = 60 minutes / 4 = 15 minutes.

15 minutes / 5 minutes segments = 3

There are 3 five-minute segments in 1/4 of an hour

Answer:

C.

Step-by-step explanation:

Answer is C. because there are a total of 60 minutes in 1 hour. We know that there is 30 minutes in half a hour. Half of 30 minutes is 15 minutes and it takes 3 five minute segments to get 15 minutes.

You can do it like this 60 * 1/4 = 60/4

60/4 = 15/1

15 = 5 * 3

Answer:

44 yards

Step-by-step explanation:

Formula :

divide the length value by 3

Answer:

55 students

Step-by-step explanation:

all you do is 220*.25 and you get the answer