The price of a computer was decreased by 10% to £504. What was the price before the decrease

Ineed to learn how to solve this problem

Kayla has a $500 budget for the school party.she paid $150 for the decorations.food will cost $5.50 per student. what inequality represents the number of students,s, that can attend the party?

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?