When you are solving for x, divide the 42 by 7. the x value equals 6.
Answer: 
Step-by-step explanation:
To find the least common multiply, you must descompose 12 and 15 into their prime factors, as you can see below:
12=2*2*3=2²*3
15=3*5
Choose the common and non common numbers with their greastest exponents:
3*5*2²=60
Now you must choose the common and non common variables with their greastest exponents:
n³
Therefore, you can conclude that the least common multiply is:

Assuming that the container and books are rectangular, the volume of both objects can be computed with the formula V=lwh, where l is length, w is width, and h is height.
As the volume of the container is 1728 m^3, while the volume of each book is 1920 cm^3. The volume for each book is converted to in terms of meters by dividing it with 100^3. The volume for each book after this conversion is 1.92 x 10^-3 m^3.
The number of the books that can fit in the shelf is the volume of the shelf divided by the volume of the books, with the assumption that the books fit perfectly in the shelf.
With the volume of the shelf divided by the volume of the books, 900,000 books can be fitted in the shelf.
I think it’s between the first and third one