6x+6y=-6
5x+y=-13
*substitution~ explain how on all steps shown

Solve for one variable in one of the equations:
5x + y = -13
y = -13 - 5x

plug that in for the variable in the other equation:
6x + 6y = -6
6x + 6 (-13 - 5x) = -6

Solve for the variable:
6x - 78 - 30x = -6
-24x - 78 = -6
-24x = 72
x = -3

Plug that in for the variable in any of the original equations:
5x + y = -13
5 (-3) + y = -13

Solve for the variable:
-15 + y = -13
y = 2

(-3, 2)

about 268 cups

Step-by-step explanation:

Assuming every cup is filled up to the top, find the area of the cone using A = pi x radius^2 x height/3. using this i got about 113.097 cm^3. Using the given conversion factor, 8 gallons is 30,280 cm^3. Simply then divide the area by the gallons, and I got 267.735 which rounds to about 268 cups.

Hope this helps :)