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Answer:
Adult tickets sold: 156
Step-by-step explanation:
Adult ticket: x
Student ticket: y
x + y = 260 ===> -6(x + y = 260) ===> -6x -6y = -1560
6x + 4.5y = 1404 ===> 6x + 4.5y = 1404
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add the two equations to eliminate a variable: -1.5y = -156
divide by -1.5: y = 104
substitution to find x:
x + y = 260
x + 104 = 260
x = 156
Answer:



Step-by-step explanation:
Given



Required
The measure of each angle
First, we calculate the length of the three sides of the triangle.
This is calculated using distance formula

For AB





So:

For BC





For AC





So, we have:



By representation



So, we have:



By cosine laws, the angles are calculated using:







Collect like terms


Solve for 


Take arc cos of both sides





Collect like terms


Solve for 


Take arc cos of both sides


For the third angle, we use:
--- angles in a triangle
Make C the subject



Answer:
C
Step-by-step explanation:
It is stating that it is 15 less(-15) than the Product of 3 and some number(3n)