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3 years ago

Evaluate 7x-1 when x= 3

Mathematics

2 answers:

irina1246 [14]3 years ago

5 0

Hello there! And welcome to brainly . com, your #1 asking and answering site!

Answer: 20

So we need to substitute x for 3, so do that. (7x-1 => 7 * 3 - 1) Multiply 7 by 3. (7 * 3 == 21) Finally, subtract by one. (21 - 1 == 20) Therefore, your answer is 20.

Hope this helped you, and have a beautiful day!! ♥

kondaur [170]3 years ago

3 0

7x - 1 = 20

7 times 3 is 21, 21 minus 1 is 20

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If g(x)= square root of 3-5x, find the domain of g'(x).

BaLLatris [955]

Answer:

domain: x>3/5

Step-by-step explanation:

First we need to derive our function g(x) to get a new function g'(x)

To do this we will have to apply chain rule because we have an inner and outer functions.

Our G(x) = square root(3-5x)

Chain rule formula states that: d/dx(g(f(x)) = g'(f(x))f'(x)

where d/dx(g(f(x)) = g'(x)

g(x) is the outer function which is x^1/2

f(x) is our inner function which is 3-5x

therefore f'(x)= 1/2x^(-1/2) and f'(x) = -5

g'(f(x)) = -1/2(3-5x)^(-1/2)

Applying chain rule then g'(x) = 1/2 (3-5x)^(-/1/2)*(-5)

But the domain is the values of x where the function g'(x) is not defined

In this case it will be 3-5x > 0, because 3-5x is a denominator and anything divide by zero is infinity/undefined

which gives us x >3/5

5 0

3 years ago

Read 2 more answers

You choose a marble at random from a bag containing 8 brown marbles 6 yellow marbles and one purple marble. You replace the marb

Andrej [43]

Pick 1: 6 yellow out of 15 total marbles = 6/15 = 2/5
Pick 2: 6 yellow out of 15 total marbles = 6/15 = 2/5

Pick 1 AND Pick 2
2/5 x 2/5 = 4/25

5 0

3 years ago

A certain bookstore chain has two stores, one in San Francisco and one in Los Angeles. It stocks three kinds of books: hardcover

riadik2000 [5.3K]

Answer:

<h2>See the explanation.</h2>

Step-by-step explanation:

(a)

$\left[\begin{array}{cccc}T&H&S&P\\S&600&1300&2000\\L&400&300&400\end{array}\right]$ = A.

In the above matrix A, the columns refers the three type of books and the rows refers the from which stores the books are been sold.

The numbers represents the corresponding sales in the month of January.

The sale is same for the 6 months.

Hence, 6A = $\left[\begin{array}{cccc}T&H&S&P\\S&3600&7800&12000\\L&2400&1800&2400\end{array}\right]$ . This matrix 6A represents the total sales over the 6 months.

(b)

If we denote the books in stock at the starting of January by B, then

B = $\left[\begin{array}{cccc}T&H&S&P\\S&1000&3000&6000\\L&1000&6000&3000\end{array}\right]$ .

Each month, the chain restocked the stores from its warehouse by shipping 500 hardcover, 1,400 softcover, and 1,400 plastic books to San Francisco and 500 hardcover, 500 softcover, and 500 plastic books to Los Angeles.

If we represent the amount restocked books at the end of each month by another matrix C, then

C = $\left[\begin{array}{cccc}T&H&S&P\\S&500&1400&1400\\L&500&500&500\end{array}\right]$ .

This restocking will be done for 5 times before the end of June.

If there would be no sale, then the stock would be

B + 5C = $\left[\begin{array}{cccc}T&H&S&P\\S&1000+2500&3000+7000&6000+7000\\L&1000+2500&6000+2500&3000+2500\end{array}\right] \\= \left[\begin{array}{cccc}T&H&S&P\\S&3500&10000&13000\\L&3500&8500&5500\end{array}\right]$ .

Since, the total sale is given by 6A, at the end of June, the inventory in each store can be shown as following,

B+5C-6A $\left[\begin{array}{cccc}T&H&S&P\\S&3500&10000&13000\\L&3500&8500&5500\end{array}\right] - \left[\begin{array}{cccc}T&H&S&P\\S&3600&7800&12000\\L&2400&1800&2400\end{array}\right] \\= \left[\begin{array}{cccc}T&H&S&P\\S&-100&2200&1000\\L&1100&6700&3100\end{array}\right]$

6 0

3 years ago

The test scores for a group of students are shown.

GarryVolchara [31]

The median is 84.5. Feel free to ask me any other questions.

8 0

3 years ago

Read 2 more answers

Complete the equations so that the solution of the system of equations is (−1, −4). y= ?X−11 6x− ? Y=10

eimsori [14]

Answer:

y = –7x – 11

6x – 4y = 10

Step-by-step explanation:

From the question given above, we obtained:

x = –1

y = –4

y = ?x – 11 ....... (1)

6x – ?y = 10b......... (2)

Let the two unknown be a and b. Thus the above equation becomes:

y = ax – 11 ......... (3)

6x – by = 10 .......(4)

Next, we shall determine the value of 'a' and 'b'. This can be obtained as follow:

For a:

y = ax – 11

x = –1

y = –4

–4 = a(–1) – 11

–4 = –a – 11

Collect like terms

–4 + 11 = –a

7 = –a

Multiply through by –1

a = –7

For b:

6x – by = 10

x = –1

y = –4

6(–1) – b(–4) = 10

–6 + 4b = 10

Collect like terms

4b = 10 + 6

4b = 16

Divide both side by 4

b = 16 / 4

b = 4

Finally, we shall substitute the value of a and be into equation 3 and 4 respectively.

y = ax – 11

a = –7

y = –7x – 11

6x – by = 10

b = 4

6x – 4y = 10

Therefore, the complete equation are:

y = –7x – 11

6x – 4y = 10

8 0

3 years ago