In a sale, there is twenty-five per cent off all prices. a chair costs £45 in the sale how much was it before the sale

First, you need to know what is 25 percent of 45, so you do 45 times 25 divided by 100 and you are going to get 11.25. Then you take the 45 and subtract those 11.25, which will give you 33.75 because it's saying how much was it before the sale. That's your final answer.

45= x(1-(25/100)) ( this is a formula to know if you want the price of something before or after or the pourcentage of the sale)
45= x(1-0.25)
45= x(0.75)
X= 45/0.75
X=60£

Idon’t understand this but 90