Question
If the coefficient of ${x^7}$ in ${\left( {a{x^2} + {1 \over {2bx}}} \right)^{11}}$ and ${x^{ - 7}}$ in ${\left( {ax - {1 \over {3b{x^2}}}} \right)^{11}}$ are equal, then :
If the coefficient of ${x^7}$ in ${\left( {a{x^2} + {1 \over {2bx}}} \right)^{11}}$ and ${x^{ - 7}}$ in ${\left( {ax - {1 \over {3b{x^2}}}} \right)^{11}}$ are equal, then :