4. Efectuați calculele:
a) (2x - 1)2 - 4(x + 3)?;
c) (3x + 1)2 – 2(2x - 3) - 2(9x - 7);
e) (2x + 3)² + 5(x - 1)² – (3x + 1);
b) (x - 5)2 + (x + 1)2 – 2(x - 2)?;
d) (72x- 3) +(73x+v2);
1) (4x – 3)2 + (3x + 2)2 – (5x – 4)?
Calculati cat mai rapid,​