-5=-5
-12+7 = x+3
-5 = x+3
-5-3 =x
x = -8
-12+7 = -8 +3
-5 = -5
Write out the "rate" as follows: 84 cents / 6 ounces
Then reduce 84/6: 84/6 cents/oz = 18 cents/oz (answer)
For this case we have that by definition, the equation of a line in the slope-intersection form is given by:

Where:
m: It's the slope
b: It is the cut-off point with the y axis

We have the following points:

Substituting the values:
Thus, the line is of the form:

We substitute one of the points and find "b":

Finally we have to:

Answer:
The equation es 