HELP PLZ. DONT POST LINKS (cause my file storage is full 0-0)

Which expression is equivalent to √ -80?

Aclothing store has the sign shown in the shop window. pani sees the sign and wants to buy 3 shirts and 2 pairs of jeans. the cost of each shirt before the discount is $12, and the cost of each pair of jeans is $19 before the discount. write and simplify an expression to find the amount pani pays if a $3 discount is applied to her total

With number 11 ( show how you got the answer)