The expression 0.07x+(x−300) models the final price of a television set with an instant rebate in a state that charges a sales tax.

enter the expression in the box that represents the price of the television set after the instant rebate is applied and before the tax is applied.

The price of the television set after the instant rebate is applied is x-300.  The tax applied portion of the expression is .07x.  In this case, the instant rebate is $300 and the tax applied would be 7%.  X is the initial cost of the TV before any discounts or taxes are applied.

I’m not absolutely sure but i think it’s 7x6x5x4x3x2=5040 because as the first character you can take any of the 7 given then you are left with 5 then 6 then 4 etc.