Keywords:
<em>System of equations, variables, hardcover version, paperback version, books
</em>
For this case we must construct a system of two equations with two variables. Let "h" be the number of hardcover version books, and let "p" be the number of paperback version books. If the hardcover version of a book weighs 7 ounces and the paperback version weighs 5 ounces, to reach a total of 249 ounces we have:
(1)
On the other hand, if there are Forty-five copies of the book then:
(2)
If from (2) we clear the number of books paperback version we have:

As each paperback version book weighs 5 ounces, to obtain the total weight of the paperback version books, represented by "x" in the table shown, we multiply
So, 
Answer:

Option D
For this, you have to understand the ratios of a 30,60,90 triangle. The ratio(in order) is x, x(sqrt 3), 2x (following the 30,60,90 pattern y'know). Well, we know the length of the hypotenuse, 4.2, so let's use ratios to figure the other sides out. The ratio of AC is x and the ratio of AB is 2x, so 2x/2=x=2.1. One side down. BC has a ratio of x(sqrt 3). We already know x so we can substitute it in. We get 2.1(sqrt 3). To calculate the area, use the formula 1/2(bh). Inputting the values in, we get 1/2(2.1*(2.1(sqrt 3)). This can be calculated to around 3.82. To calculate the perimeter, take the sum of the sides. By adding the sides together, we get about 9.98. Hope you can now understand how to do these kinds of questions.
Answer:
1 = 40
2 = 140
3 = 40
4 = 140
5 = 40
6 = 140
7 = 40
Step-by-step explanation:
A straight line is 180 so I did 40 because 140 + 40 = 180. once I figured 3 out I basically had the rest.
The size of something. Typically something that is very large.