Let x equal the number of adult tickets sold.
X + 3X=512
(I put 3x because we know the students sold 3 times as many).
Solve for X.
X+3X=512
4X=512
4X/4=512/4
X=128
Answer:

Step-by-step explanation:
The function is
where x is the number of bottles of soda.
The domain means the set of "allowed" x values.
Also, f(x) means the amount of money left, which cannot be less than 0. So we put 0 into f(x) and solve for x:

This means the highest number of bottles you can buy is 10. So the domain is anything from 0 to 10. <em>You can buy 0 until highest 10 bottles. Hence the domain is </em>

Step-by-step explanation:
2 equations with 2 variables.
the most common approach is
1. use one equation to express one variable by the other.
2. use this expression in the second equation and solve for the second variable.
3. use that solution in the original first equation and solve for the first variable.
the end.
0.05N + 0.10D = 2.20
N + D = 23
1. N = 23 - D
2. 0.05(23 - D) + 0.10D = 2.20
1.15 - 0.05D + 0.10D = 2.20
0.05D = 1.05
D = 1.05/0.05 = 21
3. N = 23 - D = 23 - 21 = 2
2 Nickels, 21 Dimes