The transfer of energy that occurs when molecules bump into one another is called...

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

3 years ago

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Choose the correct answer choice.

Dafna1 [17]

Answer:

The T shirt choice

Step-by-step explanation:

Both values increase at the same rate therefore is proportional.

7 0

3 years ago

Find the volume of a cone with a base diameter of 12 m and a height of 10 m.

dexar [7]

Answer:

=376.8 $m^{3}$

Step-by-step explanation:

V=n $r^{2}$ $\frac{h}{3}$ Where V is the volume , r is the radius and h is the perpendicular height .

r = $\frac{12}{2}$ m=6

h = 10m

n=3.14

v= 3.14 * 6*6 * $\frac{10}{3}$

=376.8 $m^{3}$

5 0

3 years ago

What are the explicit equation and domain for an arithmetic sequence with a first term of 5 and a second term of 2?

xenn [34]

For the answer to the question above asking the explicit equation and domain for an arithmetic sequence with the first term of 5 and the second term of 2? I think the answer for this is <span>5-2(n-1); all integers where n≥0. I hope this helps.</span>

7 0

3 years ago

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Three streets intersect to form a right triangle as shown below. The parts of streets that make up the legs of this triangle are

Burka [1]

Answer:

70 yd.

Step-by-step explanation:

The three streets at the intersection form a right triangle.

For a right triangle, the length of the longest side (called hypothenuse) is given by Pythagorean's theorem:

$h=\sqrt{x^2+y^2}$

where

x is the length of the 1st side

y is the length of the 2nd side

h is the length of the hypothenuse

Here we want to find the hypothenuse.

We have:

x = 42 yd (length of the 1st side)

y = 56 yd (length of the 2nd side)

Substituting, we find h:

$h=\sqrt{42^2+56^2}=70 yd$

7 0

3 years ago