Expression 3: "y" equals StartFraction, 1 Over 6 Superscript, 2 thirds , Baseline , EndFraction left parenthesis, StartFraction, left parenthesis, 2 Superscript, 1 third , Baseline left parenthesis, "x" squared 9 "k" left parenthesis, StartRoot, left parenthesis, 1 plus left parenthesis, StartNestedFraction, 2 "x" to the 4th power NestedOver StartRoot, 27 , EndRoot "k" , EndNestedFraction , right parenthesis squared , right parenthesis , EndRoot plus 1 , right parenthesis , right parenthesis Superscript, 1 third , Baseline , right parenthesis Over "x" , EndFraction minus StartFraction, 24 Superscript, 1 third , Baseline "x" cubed Over left parenthesis, "x" squared 9 "k" left parenthesis, StartRoot, left parenthesis, 1 plus left parenthesis, StartNestedFraction, 2 "x" to the 4th power NestedOver StartRoot, 27 , EndRoot "k" , EndNestedFraction , right parenthesis squared , right parenthesis , EndRoot plus 1 , right parenthesis , right parenthesis Superscript, 1 third , Baseline , EndFraction , right parenthesisy=1623213x29k1+2x427k2+113x−2413x3x29k1+2x427k2+113