( x − 1) ² + 2( x − 1 ) ( x + 3 ) + ( x + 3 )² = ((х - 1) + (х + 3))² =
= (х - 1 + х + 3)² = (2х + 2)²
(2 · 5 + 2)² = 12² = 144
( x − 1) ² + 2( x − 1 ) ( x + 3 ) + ( x + 3 )² = ((х - 1) + (х + 3))² =
= (х - 1 + х + 3)² = (2х + 2)²
(2 · 5 + 2)² = 12² = 144