Hurry

which description is paired with its correct expression?

seven less than the quotient of two and a number squared, increased by six; 7-2/n^2+6

nine times the difference of a number cubed and three: 9(n^3-3)

eight more than the quotient of a number squared and four, decreased by seven; 8+4/n^2-7

twice the difference of a number cubed and eight; 2n^3-8