Percentage - Please help I'm stuck!

[Guest]

A laptop has been marked up by 45% on cost and subsequently a 25% discount was given. if the discounted selling price was $3250 calculate the original cost of the laptop.

[Guest]

Let x denotes the original cost of the laptop.

The on cost is x*0.45 Or the latop costs x - x*0.45

But they made 25% discount so the discount is (x-x*0.45)*0.25
So the price is x - x*0.45 - (x-x*0.45)*0.25 = 3250


x - x*0.45 - (x-x*0.45)*0.25 = 3250
0.55*x - (0.55*x)*0.25 = 3250

0.55*x - 0.1375*x = 3250
0.4125x = 3250
x=7878.79