1) 36 x² + 120 x + 100 = ( 6 x + 10 )²
2) 49 x² + 28 x y + 4 y² = ( 7 x + 2 y )²
3 ) 25 a² + 10√3 a + 3 = ( 5 a + √3 )²
4) 36 x² - 120 x + 100 = ( 6 x - 10 )²
5 ) 5 a ² - 6√5 a + 9 = ( √5 a - 3 ) ²
6 ) 49 x² - 4 y² = ( 7 x + 2 y ) ( 7 x - 2 y)
7 ) 64 a² - 121 = ( 8 a - 11 ) ( 8 a + 11 )