CREATE TABLE table_name_84 (opponents VARCHAR, year VARCHAR, surface VARCHAR, partner VARCHAR)

Who was Margaret Court's opponent on clay in 1975?
SELECT opponents FROM table_name_84 WHERE surface = "clay" AND partner = "margaret court" AND year = 1975
SELECT "opponents" FROM "table_name_84" WHERE "clay" = "surface" AND "margaret court" = "partner" AND "year" = 1975