The cake density is 0.454 ounce per cubic inch and the fair price is $0.20 per ounce. What should be a fair price for each cake?

price = x * 0.2

or

price = x * 0.454 * 0.2

Step-by-step explanation:

In this case we must know either the mass of the cake or its volume.

Given the case that we know the mass of the cake, it would be:

price = x * 0.2

where x is the mass of the cake in ounces, that is to say if for example a cake has a mass of 10 ounces, it would be:

price = 10 * 0.2 = 2

which means that each cake costs $ 2

Given the case of the volume, we must first multiply the density by this volume in order to calculate the mass and finally the price.

price = x * 0.454 * 0.2

where x is the volume of the cake in cubic inches, if for example the volume is 10 cubic inches it would be:

price = 10 * 0.454 * 0.2 = 0.908

which means that each cake costs $ 0.9

the barter

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18