Answer:
A book is worth $1 and a DVD is worth $12.
Step-by-step explanation:
The equations (2 unknowns and two equations, d is for a DVD and b is for a book):
For David: 3d+4b=40
For Anna: d+6b=18
Now multiply the second equation with -3 and add to the first equation:
3d+4b=40
−3d−18b=−54
Combined equation: −14b=−14 and b=1 (means that each book is worth $1).
Now for DVD price, use the second equation:
d=18−6 or d=12 (means that each DVD is worth $12).
A book is worth $1 and a DVD is worth $12.
X = 28
you divide 112 by 4 to get 28
A billion is 9 zeroes
1.96 is already less than 10 and greater than or equal to 1 so
1.96 times 10^9 is answer
A is answer
Answer:
c. ![\frac{1}{12n} = {[12n]}^{-1}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B12n%7D%20%3D%20%7B%5B12n%5D%7D%5E%7B-1%7D)
Step-by-step explanation:
![[\frac{1}{4}][\frac{2}{5}][\frac{1}{2}][\frac{4}{7}][\frac{5}{8}][\frac{2}{3}][\frac{7}{n}] = \frac{560}{6720n} = [12n]^{-1} = \frac{1}{12n}](https://tex.z-dn.net/?f=%5B%5Cfrac%7B1%7D%7B4%7D%5D%5B%5Cfrac%7B2%7D%7B5%7D%5D%5B%5Cfrac%7B1%7D%7B2%7D%5D%5B%5Cfrac%7B4%7D%7B7%7D%5D%5B%5Cfrac%7B5%7D%7B8%7D%5D%5B%5Cfrac%7B2%7D%7B3%7D%5D%5B%5Cfrac%7B7%7D%7Bn%7D%5D%20%3D%20%5Cfrac%7B560%7D%7B6720n%7D%20%3D%20%5B12n%5D%5E%7B-1%7D%20%3D%20%5Cfrac%7B1%7D%7B12n%7D)
* To make this simpler, reduce these two fractions in lowest terms.
I am joyous to assist you anytime.
