What are the center and radius of the circle defined by the equation
x2 + y2 - 6x+By+21=0 ?

Which equation represents the partial sum of the geometric series?

What are “like terms”? why can we only add like terms?

Apublic library wants to place 4 magazines and 9 books on each display shelf. the expression 4s+9s represents the total number of items that will be displayed on s shelves. simplify the expression