Question

[tex]( \frac{1}{x} + \frac{2}{y}) ^{6}
[/tex]
Aflati termenul din mijloc.

Answer 1

[tex]T_4=C_6^3( \frac{1}{x} )^{6-3}( \frac{2}{y} )^{3}\\ T_4= \frac{6!}{3!(6-3)!} \frac{1}{x^3} \frac{8}{y^3} \\ T_4=20\frac{1}{x^3} \frac{8}{y^3}= \frac{160}{x^3y^3} [/tex]