b. In the current spreadsheet, u = 30, f = $20, and $800 is the flat commission for sales equal to or smaller than u. This means that your salesperson will collect a flat $800 for selling u = 30 pairs of jeans. Once she sells 31 pairs or more, she will collect f = $20 for each additional pair sold. Which two linear equations describe the two intervals of N(x)? Express your answer in terms of u, f, and x, where x is the number of units sold.
Interval Equation
first {x ≤ u} N(x) =
second {u

Question

b.	In the current spreadsheet, u = 30, f = $20, and $800 is the flat commission for sales equal to or smaller than u. This means that your salesperson will collect a flat $800 for selling u = 30 pairs of jeans. Once she sells 31 pairs or more, she will collect f = $20 for each additional pair sold. Which two linear equations describe the two intervals of N(x)? Express your answer in terms of u, f, and x, where x is the number of units sold. 
Interval	Equation
first {x ≤ u}	N(x) = 
second {u < x}	N(x) =