Please help with this

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

Formulate alisha has a number in mind. if she adds three to her number the result is less than five. use this information to write and solve an inequality about alisha's number. then graph the solution set.

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?