The answer is the sixth grade class.
In order to find the answer, you have to divide each grade's total by the number of hours it took them to make that money, which will give you the amount each class makes per hour.
$170 / 55 = $3.09
$112 / 44 = $2.54
$192 / 66 = $2.91
The answer is that she had 48. Set it up as an equation with x as the amount of money she started with. x - 30 = 3/8x. That says, in words, "the amount of money she started with minus 30 for the dress left her with 3/8 of the money she started with. Solve for x by adding 30 to both sides and subtracting 3/8 from 8/8x (8/8 = 1). 8/8 - 3/8 = 5/8, so 5/8x = 30, multiply both sides by 8 to get 5x=240 and x = 48.
The solution (400, 3, 200) is the answer to a system of equations which has three variables. Respectively, this system is expected to have three equations because it has three unknowns. So for example if your unknowns are x, y and z, then the answers will be x=400, y=3, and z=200.
Answer:

Step-by-step explanation:
![\frac{x+2}{4x^2 + 5x + 1} \ \times \ \frac{4x+1}{x^2-4}\\\\=\frac{x+2}{4x^2 + 4x + x + 1} \ \times \ \frac{4x+1}{x^2-2^2}\\\\=\frac{x+2}{4x(x + 1) + 1( x + 1)} \ \times \ \frac{4x+1}{(x - 2)(x + 2)} \ \ \ \ \ \ \ \ [ \ (a^2 - b^2 = (a-b)(a+b) \ ]\\\\\\=\frac{x+2}{(4x + 1)(x+1)} \ \times \ \frac{4x+1}{(x-2)(x+2)}\\\\=\frac{1}{(x+1)} \ \times \ \frac{1}{(x-2)}\\\\= \frac{1}{(x+1)(x-2)}](https://tex.z-dn.net/?f=%5Cfrac%7Bx%2B2%7D%7B4x%5E2%20%2B%205x%20%2B%201%7D%20%5C%20%5Ctimes%20%5C%20%5Cfrac%7B4x%2B1%7D%7Bx%5E2-4%7D%5C%5C%5C%5C%3D%5Cfrac%7Bx%2B2%7D%7B4x%5E2%20%2B%204x%20%20%2B%20x%20%2B%201%7D%20%5C%20%5Ctimes%20%5C%20%5Cfrac%7B4x%2B1%7D%7Bx%5E2-2%5E2%7D%5C%5C%5C%5C%3D%5Cfrac%7Bx%2B2%7D%7B4x%28x%20%2B%201%29%20%20%2B%201%28%20x%20%2B%201%29%7D%20%5C%20%5Ctimes%20%5C%20%5Cfrac%7B4x%2B1%7D%7B%28x%20-%202%29%28x%20%2B%202%29%7D%20%20%20%20%5C%20%5C%20%5C%20%5C%20%5C%20%20%5C%20%5C%20%5C%20%5B%20%5C%20%28a%5E2%20-%20b%5E2%20%3D%20%28a-b%29%28a%2Bb%29%20%5C%20%5D%5C%5C%5C%5C%5C%5C%3D%5Cfrac%7Bx%2B2%7D%7B%284x%20%2B%201%29%28x%2B1%29%7D%20%5C%20%5Ctimes%20%5C%20%5Cfrac%7B4x%2B1%7D%7B%28x-2%29%28x%2B2%29%7D%5C%5C%5C%5C%3D%5Cfrac%7B1%7D%7B%28x%2B1%29%7D%20%5C%20%5Ctimes%20%5C%20%5Cfrac%7B1%7D%7B%28x-2%29%7D%5C%5C%5C%5C%3D%20%5Cfrac%7B1%7D%7B%28x%2B1%29%28x-2%29%7D)
15 is half of 30...right. so what is half of 6...Thats your answer. because in #10 y=5x. do a similar thing with number 12. accept with looking at t instead of x for your given value