Answer:
see explanation
Step-by-step explanation:
Using the trigonometric identity
tan²x + 1 = sec²x ⇒ tan²x = sec²x - 1
Consider the left side
sec²x × tan²x + sec²x
= sec²x(sec²x - 1) + sec²x ← distribute and simplify
= 
x - sec²x + sec²x
= x = right side ⇒ verified
Your answer should be 486 inches, you do 9x9 to find the area of one of the faces, and because there is 6 faces, you multiply that answer (81) to get 486
Write a system of equations:
x + y = 125
20x + 15y = 2100
Solving:
x = 125 - y
20(125 - y) + 15y = 2100
2500 - 20y + 15y = 2100
2500 - 5y = 2100
-5y = 2100 - 2500
-5y = -400
y=80
x + 80 = 125
x = 125 - 80
x = 45
The first charges 45$ per hour and the second charges 80$ per hour
When you lay them out then you know what you are dividing
