Here is the procedure step by step. 1) Set the equation that models the
situation: gross pay = 400.00 + 0.80x, where x is the number of units
completed by the worker. 2) Substitute the value of x for 1425 units:
gross pay = $400.00 + $0.80 (1425). 3) Do the math: gross pay = $400.00 +
$1140 = $1540. Then,the answer is $ 1540.