What is 4,027 divided by 8

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

Ineed with this problem 21 show steps

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of