表达式4: "y" equals StartFraction, 8 "x" Over left parenthesis, 3 "x" plus 2 , right parenthesis , EndFraction left brace, negative 20 less than or equal to "x" less than negative 2 thirds , right bracey=8x3x+2−20≤x<−23
4
表达式5: left parenthesis, negative 2 , 4 , right parenthesis−2,4
