Slope-Intercept form of an equation is: y = mx + b where
m = slope
b = y-intercept
x + 4y = 8
4y = -x + 8
The y-intercept (b) = 2
I am not sure why you gave a point that goes through the y-intercept <em>because it does not relate to the question </em>, however, I have shown below the equation of point (6, 3) that goes through b = 2.
In order to find this, we need to start with the cost after the discount. We can then divide this by the amount in percentage that we paid. Since it is 25% off, we paid 75%.