F(x)=4x^2-2x+17 help pls

Ineed the solution to this problem and the steps.

In a sale there is 25% of all prices a chair costs £45 in sale how much was it before the sale

Ahmed plans to add a rectangular sunroom to his house. the sunroom will have a length of 14 feet and a width of 10 feet, and the construction will cost $40 per square foot. how much more would the sunroom cost if it’s width were increased to 12 feet?