Decide if the situation involves permutations, combinations, or neither. explain your reasoning.
the number of ways 18 people can line up in a row for concert tickets.
does the situation involve permutations, combinations, or neither? choose the correct answer below.

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

Raj encoded a secret phrase using matrix multiplication. using a = 1, b = 2, c = 3, and so on, he multiplied the clear text code for each letter by the matrix to get a matrix that represents the encoded text. the matrix representing the encoded text is . what is the secret phrase? determine the location of spaces after you decode the text. yummy is the corn the tomato is red the corn is yummy red is the tomato

2/3(-6y+9x) expand each expression using the distributive property