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Thetermindependent ofxintheexpansions of(sqrtx -(2 ) /(sqrt x )) ^(18)is |
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Answer» `- ""^(18)C_9 2 ^(9) ` LET` T_( r + 1 )=""^(18) c _ r (sqrt x) ^( 18 - r )(( - 2 ) /(sqrt x )) ^r ` `rArrx ^(9 -( r ) /(2) - (r )/(2)) =x ^(0)` `9 - r =0 ` `thereforer=9 ` `thereforeT_(r+ 1 )=""^(18) c _9 (- 2 ) ^(9)` `=""^(-18)c _ 9 2 ^(9) ` |
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