Question: In what state did Olivia Newton-John perform Summer Nights? 

Context paragraphs:
Gold (Olivia Newton-John album): Olivia Newton-John: Gold is a double album of Olivia Newton-John's greatest hits, released in 2005.  It contains all but one of her solo "Billboard" Hot 100 hits (excluding "I Need Love") and is the first CD to contain the track "Fool Country" (a B-side to "Magic" and contained in the film "Xanadu", but not available on the soundtrack).  The album is considered the most thorough of all of Newton-John's many compilation albums.

Summer Nights (Grease song): "Summer Nights" is a popular song from the musical "Grease".  Written by Jim Jacobs and Warren Casey, its best-known version was recorded by John Travolta and Olivia Newton-John for the big-screen adaptation of the musical, and released as a single that same year.

Olivia's Greatest Hits Vol. 2: Olivia's Greatest Hits Vol.  2 is the second hits collection from English-born, Australian pop singer Olivia Newton-John released in September 1982.  The album compiled most singles released by Newton-John since the release of her 1977 "Olivia Newton-John's Greatest Hits" album from her following albums and soundtracks.  The album included two new recordings; "Heart Attack" and "Tied Up".  Both songs were released as singles and reached number 3 and 38 on the pop charts, respectively.  "Heart Attack" was a number one single in France.

Olivia Newton-John's Greatest Hits: Olivia Newton-John's Greatest Hits (1977) was the first compilation album released by Olivia Newton-John in the United States.  (In some other regions, Newton-John released a 1974 compilation, "First Impressions".  This album was therefore marketed instead as "Greatest Hits Vol.  2" and featured a different track listing.)  The album collected all of Newton-John's American Top 40 singles released between 1971 and 1977.  "Changes" was the only track not released as a single, but it was one of Newton-John's first self-written songs that she recorded.  The album was Newton-John's first platinum certification peaking No. 13 Pop and No. 7 Country.  It ended up being certified double Platinum in the US and Platinum in the UK and Canada, and also Gold in Hong Kong.

Summer Nights (residency show): Summer Nights is the debut residency show by Australian recording artist, Olivia Newton-John.  The show takes place in the Donny & Marie Showroom, at the Flamingo Las Vegas.  The show began April 2014 and is slated to complete September 2015.

Flamingo Las Vegas: Flamingo Las Vegas (formerly The Fabulous Flamingo and Flamingo Hilton Las Vegas) is a hotel and casino located on the Las Vegas Strip in Paradise, Nevada.  It is owned and operated by Caesars Entertainment Corporation.

Live at the Sydney Opera House: Olivia Newton-John and the Sydney Symphony Orchestra: Live at the Sydney Opera House is a HD video (16:9) released in 2008 for a tour of four concerts at the Sydney Opera House of singer Olivia Newton-John.  The show was done in March 2006 with her band and Sydney Symphony conducted by Rick King.  Produced by Olivia's Gaia Productions.

A Summer Night with Olivia Newton-John: A Summer Night with Olivia Newton-John was the eighteenth concert tour by Australian singer Olivia Newton-John, in support of her sixth soundtrack "A Few Best Men".  The tour name drifts from her 1978 hit, "Summer Nights", from the musical film "Grease".  It is Newton-John largest tour since the Heartstrings World Tour, which runs from 2002 to 2005.  It was her first tour in the United Kingdom in over 30 years.

Magic: The Very Best of Olivia Newton-John: Magic: The Very Best of Olivia Newton-John is a 2001 greatest hits compilation from Olivia Newton-John.  This was the first compilation from Newton-John to include all 15 of her Top 10 hits on the "Billboard" Hot 100 and the first Newton-John album to include "The Grease Megamix".

If Not for You (album): If Not for You is the debut studio album by British-Australian singer-songwriter Olivia Newton-John, released in November 1971 by Festival Records.  The album was released on the Pye International label in the UK as "Olivia Newton-John", with a slightly different cover.  As a covers album, "If Not for You" features mostly songs previously recorded from contemporary artists of the 1960s and early 1970s.  She made several performances to promote "If Not for You" and her follow-up album, "Olivia", including an international tour with British singer Cliff Richard.  It was her first album released by Festival Records, which would release all her albums in Australia until its dissolution in 2005.  It also has Newton-John's first works with her long-time musical partner, John Farrar.

Supporting paragraphs: Summer Nights (residency show) Flamingo Las Vegas
Answer: Nevada