All categories

3 years ago

Can someone please help

Mathematics

2 answers:

Masteriza [31]3 years ago

8 0

19 hours is your answer

romanna [79]3 years ago

6 0

19 hours is the correct answer

You might be interested in

The hardcover version of a book weighs 7 ounces while its paperback version weighs 5 ounces. Forty-five copies of the book weigh

konstantin123 [22]

Answer:

33 copies were paperback and 12 were hardcover.

Step-by-step explanation:

Let h represent the number of hardcover copies and p represent the number of paperback copies.

We know that the total number of copies was 45; this gives us the equation

h+p = 45

We know that each hardcover copy is 7 ounces; this gives us the expression 7h.

We also know that each paperback copy is 5 ounces; this gives us the expression 5p.

We know that the total weight was 249 ounces; this gives us the equation

7h+5p = 249

Together we have the system

$\left \{ {{h+p=45} \atop {7h+5p=249}} \right.$

We will use elimination to solve this. First we will make the coefficients of the variable p the same; to do this, we will multiply the top equation by 5:

$\left \{ {{5(h+p=45)} \atop {7h+5p=249}} \right. \\\\\left \{ {{5h+5p=225} \atop {7h+5p=249}} \right.$

To eliminate p, we will subtract the equations:

$\left \{ {{5h+5p=225} \atop {-(7h+5p=249)}} \right. \\\\-2h=-24$

Divide both sides by -2:

-2h/-2 = -24/-2

h = 12

There were 12 hardcover copies sold.

Substitute this into our first equation:

12+p=45

Subtract 12 from each side:

12+p-12 = 45-12

p = 33

There were 33 paperback copies sold.

3 0

4 years ago

Read 2 more answers

Bonita is testing prototype model rocket engines. To be considered a successful launch, the rocket must reach a height of at lea

lbvjy [14]

Answer:

(0, 33) : Yes

(4.8, 30.5) : Yes

Step-by-step explanation:

height of at least 24 ft : y >= 24

horizontal distance of no more than 10 ft. : 0 <= x <= 10

The vertical height must be at least three times as high as the horizontal distance. No rocket should go higher than 33 ft.:

y >= 3x and y <= 33

So Constraints:

24 <= y <= 33

y >= 3x

0 <= x <= 10

Now check to see if those coordinate points meet all the constraints

(0, 33) : Yes

(4.8, 30.5) : Yes

(9, 26) : No (because 26 is less than (3 * 9) = 27)

(4, 36) : No (because 36 > 33, must be 24 <= y <= 33)

(2, 22): No (because 22 <24, must be 24 <= y <= 33)

5 0

3 years ago

A surfboard is originally priced at $155. The online retailer gives a discount and the surfboard is now priced at $93. Enter the

GrogVix [38]

93 is 60 percent from the original price.
The discount reduces the original price by 40 percent.

7 0

3 years ago

Which number is between 7/11 and 0.75( the 75 is repeating)

AlekseyPX

Convert 7/11 to a decimal value.

7 divided by 11 = 0.636364

Subtract 0.636364 to 0.757576 and divide the difference by 2.

Following the equation, 0.636364 - 0.757576 = 0.121212.

<span>0.121212 divided by 2, the quotient is 0.06 (06 is repeating) </span>

7 0

4 years ago

Y=x-7<br> Y=-4x-2<br> Solve by substitution help please

wlad13 [49]

Answer:

(1, - 6 )

Step-by-step explanation:

Given the 2 equations

y = x - 7 → (1)

y = - 4x - 2 → (2)

Substitute y = x - 7 into (2)

x - 7 = - 4x - 2 ( add 4x to both sides )

5x - 7 = - 2 ( add 7 to both sides )

5x = 5 ( divide both sides by 5 )

x = 1

Substitute x = 1 into either of the 2 equations for corresponding value of y

Substituting x = 1 into (1)

y = 1 - 7 = - 6

Solution is (1, - 6 )

6 0

3 years ago

Read 2 more answers