Lightning lucy's burnable cd's are on sale this month for 10% off regular prices. if a pack of 10 blank cd's normally costs $15, how much do you save per cd?

$0.15 saved per cd.

Step-by-step explanation:

15 divided by 10 = 1.5

1.5 X 0.9 = 1.35

1.5 - 1.35 = 0.15

hope it helped :)

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".