Alex purchased 3 packs of baseball cards that cost $2.50 each. He also purchased 2 packs of card protectors that cost $3.00 each. If tax was included in the prices, how much change did Alex receive after paying with a $20 bill?

6.50

Step-by-step explanation:

You have to add/multiply 2.50 by 3 to get the total cost of the cards. 2.50*3=7.5. then, you need to add/multiply 3.00 by 2 to get 6. 7.5+6= 13.5. 20-13.5=6.50.

the change was $6.50

there is only one way to arrange all the eight relative to each other because they are not distinct. we have

now there are nine places to place an (and not more than one in one place).   because we have four symbols, we need to choose four of these nine places to insert an . order does not matter because the are not distinct.

thus there are 1 · c(9,4) ways, or, if we calculate it,

thus there are 126 ways to form such "words."

if the angular bisector of an triangle bisects the opposite side, prove that the other two sides are equal.