2x—5x—4=2[x—5/2(x)]—4 =2[(x—5/4)—25/16]-4 =2(x—5/2)—25/8-4 =2(x—5/2)—57/8=0 ∴2(x—5/2)=57/8 ∴(x—5/2)=57/16 …