表达式6: "y" minus "s" left parenthesis, "b" , right parenthesis equals StartFraction, left parenthesis, "s" left parenthesis, "b" , right parenthesis minus "s" left parenthesis, "a" , right parenthesis , right parenthesis Over "b" minus "a" , EndFraction left parenthesis, "x" negative "b" , right parenthesis left brace, "a" less than or equal to "x" less than or equal to "b" , right bracey−sb=sb−sab−ax−ba≤x≤b
6
表达式7: "m" equals StartFraction, left parenthesis, "s" left parenthesis, "b" , right parenthesis minus "s" left parenthesis, "a" , right parenthesis , right parenthesis Over "b" minus "a" , EndFractionm=sb−sab−a
