Give the coordinates of the buyer of R & A Plant Genetics from Benchmark Education.
coordinates refer to (school_latitude, school_longitude); R & A Plant Genetics refer to item_name; Benchmark Education refer to vendor_name
SELECT T2.school_latitude, T2.school_longitude FROM resources AS T1 INNER JOIN projects AS T2 ON T1.projectid = T2.projectid WHERE T1.item_name = 'R & A Plant Genetics' AND T1.vendor_name = 'Benchmark Education'