-6x=-2(x+12) Given
-6x=-2x-24 Distributive Property
-4x=-24 Addition Property of Equality
x=6 Division Property of Equality
Given:
Book club A charges $20 for membership and $2 per book rental.
Book club B charges $10 for membership and $3 per book rental.
To find:
The number of books for which the cost be the same at both book clubs.
Solution:
Let x be the number of books.
Book club A charges $20 for membership and $2 per book rental. So, the total cost is
...(i)
Book club B charges $10 for membership and $3 per book rental. So, the total cost is
...(ii)
Equating (i) and (ii), we get
![10+3x=20+2x](https://tex.z-dn.net/?f=10%2B3x%3D20%2B2x)
![3x-2x=20-10](https://tex.z-dn.net/?f=3x-2x%3D20-10)
![x=10](https://tex.z-dn.net/?f=x%3D10)
The total cost is
![C_1=20+2(10)](https://tex.z-dn.net/?f=C_1%3D20%2B2%2810%29)
![C_1=20+20](https://tex.z-dn.net/?f=C_1%3D20%2B20)
![C_1=40](https://tex.z-dn.net/?f=C_1%3D40)
Therefore, the total cost at both book clubs are same for 10 rental books and that cost is $40.
For a problem of this nature, we need to assume that the base of the observation tower is at the same elevation as the fire. The tangent of the angle is the ratio of tower height to horizontal distance:
tan(α) = (tower height)/(horizontal distance)
Rearranging this equation, we have
(horizontal distance) = (tower height)/tan(α)
Putting in the given values gives
(horizontal distance) = (90 ft)/tan(7°) ≈ 733 ft
You add all of the numbers up each row and divide by how many there are so:
row one: if u add it all up it would be 10 then divide by how many there are