How to solve how many milligrams in one kilogram

Which of the following parabolas opens down?

Bc and bd are opposite rays. all of the following are true except a)a,b,c,d are collinear b)a,b,c,d are coplanar c)bc=bd d)b is between c and d

6. sarah saved $12.75 every week for a number of weeks, w. she received an additional $25 during the last week in which she saved money. write and solve an equation to find the number of weeks, w, for which sarah had saved money if she has $114.25 now.