Someone help and please make sure it’s right? :)

What aspects of lines have to be diffrent

Nick has box brads. he uses 4 brads for the first project. nick let’s b represent the original number of brads and finds that for the second project, the number of brads he uses is 8 more than half the difference of b and 4. write an expression to represent the number of brads he uses for the second project.

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?