Rút gọn biểu thức sau: (2x + 1)^2 + (3x – 1)^2 + 2(2x + 1)(3x – 1)

(2x + 1)2 + (3x – 1)2 + 2(2x + 1)(3x – 1)

= (2x + 1)2 + 2.(2x + 1)(3x – 1) + (3x – 1)2

= [(2x + 1) + (3x – 1)]2

= (2x + 1 + 3x – 1)2

= (5x)2

= 25x2