Need ! on a khan academy test and don"t have much time ! correct answer gets !

otto has some whipping cream that is 30% butterfat and some milk that is 2% butterfat. he wants to make a 500 ml mixture of them that is 12% butterfat. here's a graph that shows a system of equations for this scenario where x is the volume of whipping cream he uses and y is the volume of milk he uses. a graph with two lines and a point.

Step-by-step explanation:

This is correct, except that if you have two variables you will need two equations. The other equation (the easy one!) was x+ y = 100, from which you might want to solve for y = 100-x, and substitute into the other equation to get:

.30x + .02(100-x) = .04(100)

.30x + 2 - .02x = 4

.28x = 2

x = 2/.28 = 50/7 or approximately 7.14 gallons of cream

100-x = 92 6/7 or approximately 92.86 gallons of 2%

R^2 at SCC