Question 647100
Hi my name is aaron and im in 10th grade. Here is what I would do... I'm assuming you mean 20% cheaper then the regular price. Lets say "x" is the regular price of the TV, lets take 20% off the regular price. 20%=0.2, so lets set up an equation.

 x-0.2x=510

.8x=510

x=637.5 hope this helps