Dylan opened a credit card account with $625.00 of available credit. now that he has made some purchases, dylan's account only has $343.75 of available credit. what is the percentage decrease of the amount of available credit in dylan's account?

Percent decrease is amount of decrease over original amount. Thus we get
(625-343.75)/625=0.45 or 45%

First you will do 

ORIGINAL NUMBER-NEW NUMBER 
$625.00 - $343.75 = $281.25

Then you will divide that number (also known as the decrease) by the original number
$281.25 divided by $625.00 = 0.45

Then you will multiply that decimal by 100 since you are looking for a PERCENT DECREASE
0.45 x 100 = 45%

So the percent decrease is 45%

The answer is something i don’t know