Answer:
4x + 19 = 31.4
4x = 12.4
x = 3.1
Step-by-step explanation:
100 - 20 = 80%
$52 represents 80% of the original price of the MP3 player.
13 represents 20% of the original price of the MP3 player.
13 * 5 = $65
20 * 5 = 100%
The original price of the MP3 player was $65.
Check:
65 * 0.2 = 13
65 - 13 = 52
113.832 kilograms is your answer