表达式7: "q" left parenthesis, "x" , right parenthesis equals StartFraction, "p" left parenthesis, "x" , right parenthesis Over "a" Subscript, 4 , Baseline "x" to the 4th power , EndFractionqx=pxa4x4
7
表达式8: "y" equals "a" Subscript, 4 , Baseline "x" to the 4th powery=a4x4