the answer is C.
12a -18s =36
(12 adult tickets= 12a) - (18 student tickets =18s) =$36
Given:
The formula for total cost is

where, p is the price of item and s is the sales tax rate (as a percent).
You pay $14.77 for an item priced at $14.
To find:
The the tax rate.
Solution:
You pay $14.77 for an item priced at $14. So,
Total cost (T) = $14.77
Price of item (p) = $14
Putting T=14.77 and p=14 in given formula, we get



Multiply both sides by 100.

Divide both sides by 14.


Therefore, the tax rate is 5.5%.
Y = -x²
y = -7x²
<u>y = 2/3x²</u>
<u>3y</u> = <u>-7 1/3x²
</u> 3 3
y = -2 4/9x
a = amount (in oz) of solution A
b = amount of solution B
The scientist wants a mixture of 110 oz, so
a + b = 110
Solution A consists of 65% salt, so each ounce of solution A contributes 0.65 oz of salt; similarly, each ounce of B contributes 0.9 oz. The mixture is supposed to consist of 75% salt, which amounts to 0.75 * (110 oz) = 82.5 oz of salt. So
0.65 a + 0.9 b = 82.5
Solve for a and b:
b = 110 - a
0.65 a + 0.9 (110 - a) = 82.5
0.65 a + 99 - 0.9 a = 82.5
0.25 a = 16.5
a = 66 ==> b = 44
<u>9x</u> = <u>3y + 5</u>
9 9
x = 1/3y + 5/9
x - 5/9 = 1/3y + 5/9 - 5/9
x - 5/9 = 1/3y
3(x - 5/9) = 1/3y · 3
3x - 1 2/3 = y
y = 3x - 1 2/3