How many ways can six kids line up in a single row to have their picture taken?

What's the difference between: x≥0 and nonnegative integer. ?

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

Two numbers have a sum of -19. one number is x. what expression represents the other number?