Do (6x12)/2, that should work
20.50 * 0.8 = $16.40
16.40 * 0.4 = $6.56
Final selling price = $6.56
I think it is negatively skewed
A fraction x/y is a ratio between two numbers x and y.
The ratio is preserved if both x and y are scaled up or down by the same number n.
This means you can obtain any fraction equivalent to x/y by multiplying both x and y by n, i.e. (n*x)/(n*y).
Then we have 1/4 = (2*1)/(2*4) = 2/8, for example.
12x > 9(2x-3)-15
distribute the 9
12x > 18x-27 -15
combine like terms on the right side
12x > 18x-42
subtract 18x from both sides
-6x > -42
divide both sides by -6
x = -42 / -6 = 7
x >7