CREATE TABLE table_name_91 (processors_supported VARCHAR2, memory VARCHAR2, model VARCHAR2)

What are the processors supported by a ddr2 memory and the nforce 550 model?
SELECT processors_supported FROM table_name_91 WHERE memory = "ddr2" AND model = "nforce 550"
SELECT "processors_supported" FROM "table_name_91" WHERE "ddr2" = "memory" AND "model" = "nforce 550"