What album had a peak position of 6 and a certification of 3x platinum?
CREATE TABLE "top_10_american_albums" (
  "rank" real,
  "artist" text,
  "album" text,
  "peak_position" real,
  "sales" real,
  "certification" text
);
SELECT "album" FROM "top_10_american_albums" WHERE "certification"='3x platinum' AND "peak_position"=6;