STEP-BY-STEP SOLUTION:
Let original price = x
( 100% - 20% )x = $44
0.8x = 44
x = ( 44 / 80 ) × 100%
x = $55
Okay, so you are asking how they came up with 0.8 as shown in the 2nd line above which I will rewrite below:
0.8x = 44
The 0.8 refers to how much of x ( original price ) is left in the new price.
So, if:
x = 100%
Then:
New price = x - 20% = 100% - 20% = 80%
Now, to get 0.8 is as follows:
80% = 0.8
