Using Pascal's Triangle ... row for exponent of 5 is 1 5 10 10 5 1
We only need the first 3: 1 5 10
First term: [tex]1(2 x^{2} )^5=32x^{10}[/tex]
2nd term: [tex]5(2 x^{2} )^{4}(- \frac{1}{3x} )=- \frac{80}{3} x^{7} [/tex]
3rd term: [tex]10(2 x^{2} )^{3}(- \frac{1}{3x} )^{2}= \frac{80}{9} x^{4} [/tex]