Divide, Then Simplify If Possible $\frac { 2 r - 3 s } { 14 } \div \left( 4 r ^ { 2 } - 12 r s + 9 s ^ { 2 } \right)$

Essay

Divide, then simplify if possible. $\frac { 2 r - 3 s } { 14 } \div \left( 4 r ^ { 2 } - 12 r s + 9 s ^ { 2 } \right)$