Expression 10: "N" left parenthesis, "x" , right parenthesis equals "f" Subscript, 1 , Baseline left parenthesis, "x" , right parenthesis plus "f" Subscript, 2 , Baseline left parenthesis, "x" , right parenthesis plus "f" Subscript, 3 , Baseline left parenthesis, "x" , right parenthesisNx=f1x+f2x+f3x