表达式2: "y" equals negative .0 2 left parenthesis, "x" minus 5 , right parenthesis squared plus 31 left brace, "y" greater than 0 , right brace 有图表。 要进行音频跟踪，按“Alt 键 + T”。y=−.02x−52+31y>0
2
表达式3: "y" equals negative .0 2 left parenthesis, "x" minus 39 , right parenthesis left parenthesis, "x" plus 29 , right parenthesis left brace, "y" greater than 0 , right brace 有图表。 要进行音频跟踪，按“Alt 键 + T”。y=−.02x−39x+29y>0
