The cd recyclery sells used cds for $10 each and buys them for $6 each. bob paid $20 when he bought and sold the same number of cds. how many cds did he buy?

Simplify the expression 10/11(22z) + (a+5) -1

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?

The length of the line segment joining the midpoints of sides ab and bc of the parallelogram abcd is 10. find the length of diagnol ac