This is a place where some algebra really helps. First think about what the storekeeper did to reduce the price by 35%. He had the television for sale for a certain price, he multiplied this price by 0.35 to find the reduction, he subtracted the reduction from the original price and he arrived at $455.00. With some algebraic notation you can say this in a much neater way.
Let $P be the original price. Multiply by 0.35 to get the reduction
reduction = 0.35 P
Subtract the reduction for the original price
new price = P - 0.35 P
The new price is $455.00 and hence you get the equation
P - 0.35 P = 455
Solve this equation for P.